I would be really hurt and probably consider dumping the person. Sad that sleeping with someone else made him realize he loves you. Sounds more like guilt induced fear that he's going to loose you...not real actual love. Plus, you should be with someone who loves you for better reasons...such as because you're a good person, etc...

See http://www.answerbag.com/a_view/2691789 . There are other relationship links (and my answers) in my profile.

Were you exclusive at the time or dating other people too? I think one minor indiscretion should be forgiven if he is being honest with you and wants to become serious, just impress on him that once you are exclusive then it is never to happen again or there will be consequences...have to admire his honesty if things are getting to be serious with you, he cares enough to do that much for you and risk everything.

i think you should forgive him! it was a drunken mistake and so forgive him

I think is a bad starting to begin with, but is up to you, me personally even if I love him I would dump him I could not live with the fear that he could do it again or worst give me an STD or worse HIV

i forgave my boyfriend for doing the same thing.. he's tried his best to make me happy ever since. however.. there are many times in our relationship where i wished i broke up with him at that time.. it would have saved me more heartache because until now, i still have insecurity issues after what he had done. in your particular situation however, i would have broken up with him not only because of the one night stand.. but because he "realized" his "love" for you.. right after he cheated. personally.. i wouldn't want that to be the reason why someone fell in love with me. i want someone to love me because i make them happy and among other things. he seems to be the type of person that rushes into things without considering the consequences.. so he slept with you.. and then slept with another girl.. and then professed his love for you.. what next? he doesn't love you anymore? he loves you again? i really don't think your boyfriend understands the meaning of love. i'm really not sure what you could do at this point.. i would've broken up with him long ago.. if he still mistreats you and abuses your feelings, i'd get out and find a healthier relationship. otherwise, if he's truly changed i'd give him a second chance

it tepends on your mentality. I do not think being drunk mitigates anything because you CHOSE to get drunk. I am not of the mentality "once a cheater always a cheater" but I compare cheating to be like 3rd degree burns over most of the body. the relationship MIGHT survive and even recover to the point of being somewhat healthy, but the scars will remain forever. both parties are better off with a fresh start elsewhere.