You won't be putting anyone in the middle of anything they don't want to get in the middle of. We know a lot of couples, and frankly, some of them don't really like each other. That's not our problem. Now, we don't intentionally put them into situations where there might be a catfight or something similar, but we do invite them all to our house for a party. They usually all come. They're civil to each other, they have fun together - they don't play together, but that's their business. Again - you're worrying about others when it isn't warranted. Let them get to be friends with those other people - then when they tell your friends that they're swinging the wrong way, they'll see for themselves.
So if you turn up in the same place, let them feel awkward. Don't sweat it. I'm sure you work with people you really don't care for. If you run into one of them at a party, do you leave in disgust? Hide in a closet? Search out the nearest Denny's and have breakfast? I doubt it. This is no different. If you bump into them at a club or party, be civil to them, and then go have a good time. Again - don't sweat it.
You can be friendly, just be wary of letting people get too close too fast. I know I come off like a cold hearted bastard when I say we don't associate with our lifestyle friends outside of lifestyle situations, but it's situations like the one you find yourself in now that made us think that way. I got tired of being Father Confessor, and Lin got tired of being thought of as a good lay, but other than that, "Hush girl - grown-ups are talkin'..." Well, bullshit. You two got into the lifestyle for a reason - I'm willing to bet that reason had nothing to do with drama, head games, political bullshit, or worrying about who is going to show up where.
Ok, you met a few duds - everyone posting on this board has done it too. It's time to get back on track and remember why you two got into swinging in the first place, and forget about the duds you've met. That's behind you - live and learn, you know? If this latest couple tries to make trouble for you, put it right back on them. Certify the profile of the friends you're worried about them getting too close to. Let them know what this couple tried to do to you - as a fair warning, not spreading drama. Go to parties, go to clubs, and, most of all, have fun. You two don't owe anybody anything, so don't feel like you're obligated to anyone. If you bump into them someplace, big fat hairy deal - let them deal with you, rather than you getting all timid and dealing with them. What I mean is, have a good time - no matter who's there or whether or not they're watching.