Having had sex with a married woman (she was 21 and married, and her husband was a complete ******* to boot, I met him, coworkers met him, and she needed something better so i decided to show her that she could do better and needed out of that relationship) I can say that it does bring about a pissload of problems. It really isn't worth the drama.
I can safely look back at what I did and regret it. Now, most people say you shouldn't have regrets but I do have plenty on this. Sure, she's way better off now (and not with me i might add) but she did end up getting hurt by me, and her husband and then her following boyfriend all as a direct result of that one night stand (yeah, it wasn't a long term affair, mostly because of my horrible temper though).
Also, having matured 3 years since then I can safely say that I would never want that done to me. (Her husband obviously didn't care as he was with someone new the day afterwards and he promptly burned all her **** and killed her dog which she had to leave with him.. yeah, speaking of psycho ex's, glad he couldn't find me.) I am not the perfect man, and I probably never will be. Everyone has flaws that drag them down, in my case it is my temper and far to often is has bitten me in the ass. I would honestly hate to think of my wife (or girlfriend) being pissed off at me and going out to a bar o something only to be picked up, macked/nailed, then let go and sent back to me. Yeah, most of you will say "then take care of your woman" but that to me speaks almost volumes about the maturity of your mind or the simple lack of caring (or morals) on your part. Granted, not everybody has the same opinions or morals depends on your upbringing and all that. But in an age where 50% of relationships end in divorce (and about 75% of relationships suffer from some type of infidelity, whether they tell their partner or not... that's half of the couples that STAY together.) means that only about 25% of relationships are actually faithful ones.
Speaking as someone who has been cheated on (and not for my lack of ability in bed, it's mostly my lack of emotional intimacy and my temper.. so I keep being reminded) and cheated on more than once it never feels good. Regardless of how much of a mack daddy you think you are, or how suave you think you are, the fact that you could go out and take someone else's with/girlfriend actually speaks volumes about your character and lack of conscience, which sooner or later will catch up with you. You may sit around here saying all you want is just fun sex and to meet people, but you can meet people without sex and you can have fun sex in a committed relationship (your own preferably). You may say you aren't searching for 'love' because you've rationalized that it doesnt' exist, bottom line is, it does exist and that's the 25% of couples who have a happy, committed relationship without any infidelity.
One day, you may find that girl that you love and want to be with. How would you feel about her going away on a conference and getting banged by someone else because you weren't 'satisfying her'. Say what you want, you'd be hurt, no matter how suave you are. Yeah, you may think you'll move on and be fine because of your confidence or whatnot, but if you thought it was real love and you wanted it more than anything in the world, you'd be shattered.
Do unto others what you wish they would do to you.
Kudos to all the REAL men who can look at a woman who's looking to cheat and tell her "Go home, you're committed. If you aren't happy, talk to your husband about it or get a divorce."