We have done this many times. It was something I would talk about during sex for a while. We chatted. Hubby actually wasn’t too keen on the idea. Thought it might get awkward.
Anyway! We went on fab swingers. Made a couples profile. Made sure we put up decent pictures. Defo helped that hubby is 6ft 2 and in good shape. I led the chat with people which tended to put them more at ease. I was open about what I wanted. Asked them what they wanted and made a few connections.
I wanted see him fuck someone the way he does me. The beast within aloud out. Safe to say he didn’t disappoint. She wanted to explore a females body while a man told her what to do… Lots of fun.
So you can find people. Defo believe it needs to be led by the woman on these forums. Too many fakes around. Photos and videos are your friends.
We paid for an experience in Vegas. Will never do that again. We thought it would be an easy way to try it. She was beautiful but there needs to be a connection.
One of the FB girls is now a very good friend. She often comes over when hubby is away. He knows and doesn’t mind. Wants it to only be the same person now. Will happily watch but doesn’t often join in. Just not his thing. More time for me 
You should try again if it’s something you want to do. Oh and pay for the premium. It’s only £5 for the month people are more likely to engage as you have committed. Also make sure to verify your profile. And your profile pic should be a little naughty but not blatant cock I’m pussy or his dick. Keep those private for friends only and have a couple of decent pictures on your profile. Keep your face out as you have know which neighbour is on.
You can also set your location at a different place to where you are which is a good thing. We would set it 20 miles up the road to be safe. We spotted someone we knew on there and hubby almost deleted the account.
Those unicorns can spot a man pushing a woman into something a mile off. You might find that some will want to video chat for a bit first. That was also fun. Had a woman watch us have sex. She then proceeded to squirt over her phone. Oh my that got me going. We traveled 150 miles to meet her and ended up staying for 3 nights.
Just be sure to be open with your partner and remember you are both in it and want to enjoy the experience. It’s not just about a man living out every porn hub threesome. In my experience it is so much more enjoyable with great communication. Before, during and after.
Hope you find what you are looking for 
You might also find it easier to find a couple. We have done this a few times. I don’t want to be fucked by another so set the rules. We could play and watch them…