Coincidentally this morning’s BDSM dare card said “You will masturbate for your partner with your legs wide open.” so I knelt between her legs with me knees apart so that both our legs were wide open and we watched each other masturbate to orgasm.
Once for me. Lots for her.
Same - mature loving couple. We both want each other to have a good time and as our bodies age we adapt. I actually had a post in another forum as I need to “take things into my own hands” to finish - so curious what others do to “get there”. I love getting her to climax and that gets me going - but usually need to take care of my own business.
So I guess to the original question asked - I think you need to talk with your partner about what she will and won’t enjoy and its ok if “hey thanks but not again”. I know when I am helping her I am also helping myself as well - so maybe that can be your jumping off. Not sure if original question was for couple play or some alone time.
So not sure if you are “hey I am going to go to town on myself” and you can just be over there reading a book. Or if it is part of your time together. Regardless talk to her a bit and especially during it so that she knows what you really like.
A lot of the time while I am eating her out - I will be masterbating at the same time and she seems cool with it. Also there are time now where I am caressung parts of her body and she now will start to masterbate - oh my god it makes me loose my mind - i love it.
I have also intiated our time together by starting to play with myself and she seems to like that as a signal as well.
I haven’t just popped into bed and gone to town on myself full throttle so to speak and then said “no I have it”.
So just speak with her and kind of introduce it as as you doing other things and say “Oh my god - looking at you I just want to jerk off all over you”
Some partners like it when you cum all over them and well you have to jerk off to do that. So don’t make it a black or white thing - but kind of integrate it into your love making.
If she is jerking you off - tell her / show her exactly what you want.
I love masturbating in front of my wife, i just tell her how much she turns me on and how she makes me so hard. She loves to watch but i love it more when she kisses and licks my kneck and nipples. She might be a bit shy at first if your never done it in front of her before but the fact your doing it because she turns you on should turn her on. Good luck
OMG when she bites my neck - oh my god,
Such a turn on
When we were first married she asked me to beat off for her. I did. Came on my belly. Since then I’ve done that in front of her when she’s on her period - she asks me to.
My oh loves when i do it and i love it when shes does it infront of me 
we was on holiday a coupke weeks back and had a private balcony where the bedroom window was so i said to her 1 day come here and i was sat on thw bed facing out thw window wanking as she watched, then got told to stop so she could fuck me.
My sex drive is much higher than my wife. Due to menopause so I masturbate more frequently. We have movies of us which she’s happy for me to use. One day I just started jerking off while laying on the lounge as she works from home. I didn’t hear her come out of her office. She watched me and said it was a massive turn on especially when I came. There is nothing hotter than when u are both comfortable enough to self serv. 
I have a vibrating cock ring and she will use that on herself and I love it. I think the thing is - you not only just “allow” them to do it - but then are verbal about how you feel. I love when she does it as it sends me the sign that she is comfortable with herself and I can be comfortable with myself. The big thing is communications and saying - I love that or not as big a fan but if you like it that is ok.
At first she didn’t like the vibrating cock ring but now she does. I want to try some other things. I do want to try a prostate massager - but just not there yet.
I would love to feel comfortable with pleasuring myself in front of my partner. I love to watch her playing with herself it is so hot and I love when she bites her lip when she climaxes and flushes
Just start doing it. Say how much she turns you on - I best she will get even hotter.
Not saying it’s a commonality among all women but speaking for myself I can say it’s an amazing turn on to have a guy masturbate in front of me.
I dated a guy who was really into finishing while jerking off and looking at me. It turned into a thing for me moving forward. Tell her you want to look at her and appreciate her while you get off and see what she says.
I love watching my hubby pleasure himself, really gets me going and I then want to join in and play, use my mouth to help him!
I want him to feel comfortable to masturbate in front of me in our bed together, rather than feeling like he has to hide it from me.
Facing each other and taking turns watching is a huge turn on for us both
( as a recent addition to this we’ve tried standing behind the bedroom door and peeking 
) its added an extra kick to being watched
I would not mind if my husband did this but he seems to prefer me to either use my hands or mouth on him. As an aside i used to have a cat that would do this, he had a little toy goose that he would carry around and he would bring it over to me and then start humping it and be looking at me all the time until he finished. Thing is he was neutered 