When dealing with uncut men, I always take more caution to pull the fore skin back with my hand to expose his crown/head. It's my understanding that uncut men are more sensitive around the head and rim. I always be sure that the stimulation I give him in that area isn't too much and that he is comfortable. I am always sure that my lips and mouth are dripping with saliva as I plasure him orally, the skin becomes very tight and I certainly do not want to rub him raw. The technique isn't that different from giving oral to a man who is cut,just a slight variation. In my opinion, IT'S ALL GOOD!
If someone you swings with starts to have feelings for you, first you certainly would tell your spouse/partner! You must always maintain an open, honest communication within your relationship. I would not only tell this "too attached" swinging partner that it's inappropriate, I would also tell them that you do not share those feelings, that you have told your spouse/partner and that you will no longer be swinging with them. You may want to stay friends but I would advise you to place distance between you and them. This kind of situation happens much more often than many of us may realize. Those not into polyamory do not accept this while swinging but there are many polyamorous swingers. For you in this situation, simply move on.