I know this is a touchy issue that can have some very biased points of view depending on what side of the fence you sit on with this...but here goes my 2 cents worth...
First of all lets put it out there...I am one of those guys that is playing without my partners consent. Secondly I want to confirm that I in no way condone the fact that I play without consent as not being wrong. It is totally the wrong thing to do to ones partner. But I must agree with dicktracy that at the end of the day it is me that will need to answer to the big guy.
I see many comments from swinging couples with regards to the trust issue. How can one trust a guy that is unfaithful? To counter this I will say that those guys that are admitting up-front in their profiles that this is what they do are the trustworthiest of all. They have had the decency to inform all of their situation...it is now up to those deciding whether they want to interact or not. I shudder to thing about all these "single" guys that they have shared with that are not really single. In my view these are the ones that should not be trusted, yet they are the ones that are accepted by the few that do not do proper checks.
On the trust subject again...why do these married guys do this and openly admit to so on their profile? Maybe they have home issues that they are still working through (in reply to a comment as to why we do not try sort out our home matters instead of trying to cheat on this site). Perhaps this site or activity is a way of releasing built up stresses that may totally collapse the marriage before the issue can be totally sorted. Would it not make sense to let the couple try and resolve their issues...while allowing the one partner the benefit of the doubt to not just break it of in sheer frustration? Again in my view it is the persons that admit openly on this site that are the persons that are the most trustworthy...they don't want to do anything to jeopardize what they may be working on back at home. I must also add that there may be persons with no intentions of resolving their issues at home...catch 22 to my post here I guess...
Again this trust I keep on hearing about...trust in what? I read many profiles where couples are looking for other persons to share the bed with...not for emotional reasons, as according to them, the act of sex is just a physical thing. If that was the case, what trust are they looking for? Is there concerns that extra persons will fall in love and run away with the other partner? Surely a guy honest enough to admit his marital situation will not do that...he has too much to lose.
Sorry for this being so long but in conclusion...don't be too hard on those (male and female) that play without consent, there may be issues that others do not know about (and there may not be...there I go contradicting myself again lol). The way I feel is that as a single playing member on this site I am the minority and therefore need to play by the rules of the majority. This means that you couples have the last say when it comes to a single member joining you or not...leave it at that and do not judge.