...Im glad none of you have said im mental and think i have a point!
i suppose ill have to have a bit of a chat with him and see if he can accept a no and if not then i guess its the boot.
Could I say he is being totally unreasonable too, and as usual you just have to flip round the viewpoint, which is quite easy here, a threesome with another guy...
How uncomfortable does he feel about that? But he wants you to go through the same kinda thing 'for him'.
Maybe point this out to him, but if he's doing the "guy thing" of everything being your fault then I guess you know how much he values you, and the relationship...
You're not being unreasonable at all, I think he is. If you both really want to experience a 3 some and are worried about potential jealousy, limits being crossed etc I would recommend an escort instead if him trying to pick up a girl. They are professional, used to dealing with this and it removes most of the emotional concerns, that's the route we went and it worked out for us, we decided to keep it exclusively with escorts so no emotional bonds could ever form.
We're kind of in the same boat. He wants a threesome, I'm not bothered either way. No men, I'm bi so I'm happy with that, not really into men except him. But the source is very important, we are looking at escorts or swingers. Him flirting with a woman then trying to convince her to let me join would be a big no no, what if she only says yes to have sex with him and ignores me. The woman neutering needs to know what you want from this. What I would recommend if you don't want to go down the more formal route is that you flirt with women and try and introduce him. It will build your confidence with women, he can watch you flirt and kiss other women. And you know the woman is interested in you. What's most important is that you actually want to do it and aren't just doing it for him. That you go at your pace. That you agree to each others rules and are confident the other will follow them. And that he's not just using you to fulfil his fantasy.
People sometimes believe that bi means we are OK in threesomes, we still get jealous though. If you don't want it say no and relate it to how he won't let you go with a man.
Hopefully I can be a bit of help as a student myself. First of all, what happens in student accomodation isn't as private as you imagine and if you wanted to keep this quiet then it's not the place to do it. Definitely don't just spring it on whoever you take home that there are two of you - I can't see that going well.
I actually met up with a couple who were looking for a woman to join them for a threesome. In my case, I was told the girl was curious about other women and that was the main reason they wanted a threesome. However, it was really clear from the beginning that they weren't 100% happy. The guy was very interested, but the girl came off as incredibly jealous and didn't enjoy herself at all. She didn't want me to kiss him - which as you've noted was pretty awkward. It ended up being an hour of me and the guy trying to do whatever she liked, which wasn't enjoyable for anyone else.
I don't know whether it didn't work because of her (she was a bit of a princess) or because she was surprised at how she actually felt when someone else was involved, but unless you are both excited to do this and have clearly agreed upon boundaries, I don't think it would work. It sounds like you have a lot of justified fears about this - so I would hold back on doing it until you've resolved them. 
I think he's a bit of a tit of you ask me from what I've heard.. he's basically asking for permission to go out and cheat on you, then bring you in last minite so it's "ok"...
It's selfish and unreasonable.. especially the kissing part ( totally agree )
I thinks its obvious you shouldn't go threw with it at your home. Try Fab Swingers and try and meet someone there. You be in control and in charge. You pick the girl and you decide when it happens. Don't let him have control.. he still gets his fantasie and you get your peice of mind..
As many have stated, he is being unreasonable. Me and my husband are open to many things, but the one thing we always agree on is we both have to feel the exact same about something. We've spoken about three some sort many times and we both feel the same, he doesn't want another man touching me and I don't want another woman touching him. We enjoy the thought of having sex infront of other people and also watching other people but we would never risk our relationship just to have a threesome. He screams selfish to me, he isn't thinking about your feelings at all.
the mrs and i have been together 19 years married 12 years i have asked suggested to the mrs about the 3some idea and we have spoke about it she wasnt and is not keen on the idea so i havent pushed it
obvoiusly being male im thinking 2 females and myself 
the mrs is not bi or bi curious so maybe thats not for us
but horses for corses as they say
i do think your partner is being a bit selfish its your body and you should choose who exsplores no one else and if your really not comfy with it then dont do it hun
he should respect your bounderies you shuldnt be made to feel this way xxxxxxx
We fantasise about a 3-some a lot, my wife is flirty by nature so does get a fair amount of attention when she's out. Both of us want it to be with another man, we've corresponded with a couple of men she'd chatted with, swapped photos etc but it's them that bale out the moment a threesome with the husband is mentioned! The thought of being naked with another naked man/'crossing swords' etc seems to dent their delicate egos! What's wrong with most men??? We are very sexual, we've both had 3-domes in other relationships, my wife and a friend were totally nailed by 4 Australians in a hotel when they were at uni! I get turned on by wanting to see her pleasures, she gets turned on by getting fucked in front of me and having 2 cocks at once. Come on men, get a grip!!!
We fantasise about a 3-some a lot, my wife is flirty by nature so does get a fair amount of attention when she's out.
Both of us want it to be with another man, we've corresponded with a couple of men she'd chatted with, swapped photos etc but it's them that bale out the moment a threesome with the husband is mentioned! The thought of being naked with another naked man/'crossing swords' etc seems to dent their delicate egos!
What's wrong with most men???
We are very sexual, we've both had 3-domes in other relationships, my wife and a friend were totally nailed by 4 Australians in a hotel when they were at uni!
I get turned on by wanting to see her pleasures, she gets turned on by getting fucked in front of me and having 2 cocks at once.
Come on men, get a grip!!!
That's great for you ifyou both get of on it. Please don't tell the rest of us to get a grip as if we men are weak or wrong for not wanting to share our loved one with others.
Your views are welcome but don't judge others.
Its not my intention to offend. But it should niot be yours either.
It's your body and your sexual relationship. I don't think there's a single way to be unreasonable here since it's one of the most intimate thing you can do with eachother.
If you have even an ounce of doubt for whatever reason, I think that you will get hurt. Is there a way you can ease into it? Have a few sessions with touching a third person, without going into the full act? You can then see what you are and aren't comfortable with while it's happening and therefore set up boundaries to ensure that it's safe and fun for all of you.
I like the idea of sharing my wife, but there's also the point of not sharing with anybody for the sake of fulfilling a fantasy. I'm afraid that if it didn't seem like a good fit then I'd like to think that as a couple we could respect each others feelings on this matter and walk away.
To me, there needs to be some kind of chemistry, not love, but some kind of respect and attraction, rather than raw animal lust. In truth the latter probably is the simple way of doing things, without emotions getting in the way, however I love my wife to the point where whoever and whatever relationship we have with people (doesn't have to be sexual) there needs to be respect and trust all round.
It's a mute point because this is my fantasy, not hers, so that would be a no anyway, but I hope you get what I'm trying to say.
Dump the scrote. He doesn't love you.
Probably rare these days but I've been married 37 and a half years and never cheated... sex gets better and better because we love each other, trust each other and know each other.
Not judging anyone, just giving my personal point of view.
With any relationship there is always going to be a bit of give and take, but in the end anything you do should be mutually agreed, and for everyone to be happy with the situation. You should be treated as an equal, and I don't think he's doing this.
It sounds as though you have some serious reservations about this, and I think you're right to have them.
My OH and I have things we'd both like to try, but we always - without fail - discuss them with each other. If there are any points we can't agree on or compromise on, we simply shelve the idea.
Perhaps you could show him this thread and gauge his reaction... I think that would enable you to see what he really wants from your relationship.
if you are interested in trying out a threesome it has to be something you are comfortable about. Do you wish to experience a threesome with another female?
He sounds like he wants to have a threesome with 2 women and it's his fantasy.
im straight and have had a threesome with a couple and was very comfortable being in a room with another male and we both pleasured his wife jointly and seperatly
I'll just add my $0.02 that may differ a bit from others.
Firstly I think in any relationship people need to be very very open about what they like or don't like and especially fantasies they have. Understanding your partner's sexual preference is imperitive to having a healthy sex life. Too many people focus only on the feels when getting into a relationship and not other things like longer term goals, values, sexual compatibility, preferences for raising kids etc.
In this case sexual compatibility is the main thing that is of contention and in my experience it would be much better if two people were very compatible but I believe that two people that aren't can make it work if there is open communication, respect and compromise. I agree with most that he is being uncompromising but I don't have enough information to conclude you should dump him especially because I've been in situations like this.
You guys need a very open and honest discussion. Find out how much this means to him to be comfortable in life, as in will he be fine if this does not happen and get him to respect and acknowledge what's an absolute no no for you. Talk more about compromises which might take some imagination. For example in my case it isn't so much she doesn't want me to have a threesome in general, she just wants to make sure the other party is absolutely no threat and she is fully comfortable with her. So for us we need to ensure we develop a good relationship with the other party first. No random hookups.
When he says no other men for you, did you discuss with him why that is? If he's jealous or insecure, did you get him to acknowlegde the double standard? Did you do enough to ease his fears? Again for us, we agreed that if she's going to be fucked by another guy he can't have that much bigger of a cock that I do, preferrably smaller. I'm a bit above average and she needs to play in that space for me not to feel too intimidated. Think outside the box, perhaps maybe there is kissing but nothing tender nor long. Perhaps maybe he needs a hallpass to have a threesome. Obviously only agree to what you're comfortable with but ultimately it's about open discussion and compromise. If you guys are open, respect each other and can't come to some compromise and this is an absolute necessity for him in life. As in he will be long term unhappy if it doesn't happen then yes it likely isn't going to work out for you guys.
Well I agree with the above and all comments that are here. I know fantasy do come up but it best to talk about. I spouse if you are married and have threesome it all depends i think for a man most would love only woman but to be 100 faithful to your partner some but some fantasy should stay in fantasy world as some fantasy can break a marriage also like threesome. If you are single then I suppose a three some is ok but that just my thoughts on this.