im the one that has been cheated on in my marriage... 3 times... and forgivness is not easy!!!
Before we got married i made it known how i felt about marriage, and told him if he felt the NEED to go elsewhere, to talk to me about it and it would be something i would consider... however he STILL went behind my back and did it... it did ruin our relationship, its been over a year now and still struggling...
I never stopped offering sex, infact he was the one to withdraw from our physical relationship, and even now im lucky to get sex 2ce a week even though i offer on at least a daily basis!!!
As far as I am concerned, i can get past the fact he was screwing someone else, but i juts cant get over the lies... it means i can never truely trust him, and am always questioning him, which i hate, and im sure he hates too!!!
Now, on the other side, he now allows me to attend swingers clubs on my own, he does not come with me as he doesnt want to be with anyone else anymore... i dont have sex with other men as a rule (although on occasions i have, and he knows everything)
I guess in my opinion, cheating (behind your partners back) is the lowest of low... I think it shows a lack of respect to your partner and kids... If your not getting wat you need from you partner, talking, counselling etc are much better options, and if all that fails then divorce! at least it would be on better terms than if your caught out having an affair, then itll be a nasty divorce!
I do not judge people though (nothing personal meant in any of my comments) i myself have cheated on some of my ex's, but hated myself for it after... and some close friends of mine are regular cheats... each to thier own