What would you do if  a friend or acquaintance told you your boyfriend was cheating?
343107
I wouldnt rush into assuming that he is, but I'd keep a close eye on him.
258425
FEEL MESSED UP! BUT WHAT CAN YOU DO. just hope that she don't find out and please don't get serious with him, he going to cheat on you just like how he is cheating on her with you.
560209
Before you do anything,find out the truth.Either of them could have been lying.If it turns out your friend lied ,apologize to your now ex and dump the friend.
656836
Assuming you meant Cheating not cheaping :o) \n\nThe first question you need to ask, is to ask yourself who is more trustworthy in this situation your friends or your boyfriend? \n\nThey may know that he is sneaking around behind your back or your friends may just want to mess your relationship with your boyfriend on purpose. \n\nThen second ask your friends why they think he is cheating on you (Do they have proof? Seen him with others? Who?) and if they do you need to ask your boyfriend if what you have heard is true.
923522
OK, lets look at your question...  "while I was housesitting this week I accidentally ran across undeniable evidence that he has a boyfriend".\n\nNo, you did not "accidentally" run across "evidence", you were being nosy. To justify you being nosy you then turn around and say "he's been LYING to me over and over for months and months". If you feel so hurt and angry, how do you think he will feel when he finds out about what you have done while housesitting? Yes, you should confront him...  about you being judgmental and not being the true friend that you have pretended to be to him.
1079914
Go on Cheaters or Talk to him urself and find out whats going on. If he doesnt tell u the truth. Go with ur gut instincts and leave his sorry butt.
275988
it has to be a mistake unless you are the one cheating.
980663
You need to tell your girlfriend her husband is cheating on her. She is in jeopardy in more ways than one. You should be more concerned with her well being that keeping a cheating lying friend.
934167
I know you don't want to hurt him, and he would probably never want to know that his mother is cheating on him, but it would probably be the worst if he finds out that you knew and never told him.  Especially since the friend told you everything, and is aware that you know of the affair.
21761
You say you are friends I would tell him.  The real question is "If he finds out on his own and discovered you know about it.  Would he get mad a you? \n\nIf you can try and get a picture of the cheating GF and show him.  As they say a picture is worth a thousand words.
1043467
yes I would be furious and think he was cheating or looking to. If it was innocent they wouldn't be using fake names and keeping it from you. If they were just friends he'd have no problem telling you
1130815
If there was absolute proof he was lying, i would confront him about it.... If there is one thing in a relationship I cannot stand is someone who is not honest...  No one deserves to be lied to.
570486
cheating is cheating... and what's to stop him or her from doing it again with someone else?
525853
i think you should tell your friend cos if you'll are true friends she will know that you are doing this in her best interest i am saying this because my best friends boyfriend was doing the exact same thing to her and i told my friend that she needs to put her foot down and confront her boyfriend cos if he truly loved her he wouldn't treat her that way.  it's harsh but sometimes you have to be firm with the people you really care about.
391621
i think if a friend told me that my man was wit another girl i would confront him for sure, find out wat was goin on and if i need to get more information first i would, u no wat us women do best investigate b4 i confront him, and if all is true i would leave him, cuz i no that i would b able to please my man in every which way therefore he would have no reason to cheat apart from greediness and if that is the case he will do it again!!!!!!!!!!!!!
404843
Think of it the other way around.  Say that he is wondering the same thing.  If he was honest enough to tell you about it, what would YOU say and do?!  Your boyfriend deserves your honesty: at the very least, have the courtesy and the courage to let him know how you are feeling.  And be prepared to crush his feelings.  If you play the cheating game, YOU KNOW it will eventually come around to bite you on the ass!  Whether it's your guilty conscience, or the inevitability of his finding out some time anyway, he WILL find out!  Do you know the difference between right and wrong?  Of course you do!  Are you willing to risk your relationship with your boyfriend?  If you are, you have no business being his girlfriend, and he's much better off without you!  Like you girls say about us, think with your big head (you know what I mean!).
315689
I'd let him go. Once a cheater always a cheater. If you can't let him go make him stand on the sidewalk by a busy road holding a sign that says "This is my punishment for cheating on my girlfriend". I saw a guy on the news who did that to try to win his girlfriend back.