My Bestfriend is Cheating on my Sister, What Should I Do?

You should confront you best friend and tell him its wrong especially doing it to your sister, it should'nt happen to no one, if he doesn't change you got to tell your sister, in the end she would appreciate it.

If he is kissing another girl in front of you, he has some nerve. This is not a friend. He is a user. He wants you to play along with his cheating game. You need to ask yourself this question, who is more important in your life? Is it your cheating, deceitful friend, or is it your sister? You should confront him and tell your sister. It is obvious that he thinks the male code of honor prevails here and that you will let him do whatever he wants.

he is a dog! I think you need to break it to your sister.. just let her know.. he may be your friend but that is your SISTER. its pretty odd that he is just doing it right in front of your face that is so disrespectful.. if he would do this what more would he do?? she needs to know..

You should tell your sister. She's only 18. It's not as if she's married to the guy, and she certainly doesn't need to be getting involved with this cheating toad at this early stage in her life.

definetley tell your sister what is going on because if she dioes find out in the end and she knew that you knew and never told her she might even fall out with you, even if your friend doesn't speak to you after it, you can still get plenty more friends because it's natural that friends do come and go in the ned and your sister is your family she'll be always there to help you if you needed it and obviously he has no respect for your sister and this is cruel tell her to leave him and get somebody who loves her and treats her with respect because he obvioulsy hasn't got any respect for her if he's doing that!! good luck with whatever you decide to do!

I'm wondering how you even got in this dilemma, because if I was in your situation, I wouldn't be letting my friend do this stuff. First, I'd tell him to stop being a jerk. Of course, being a close friend, I might give him a little more leeway than I would if I found out a stranger was cheating on my sister. Think about it: If your sister's boyfriend wasn't a friend of yours, and you saw him at a bar messing with another woman, wouldn't your first impulse be a desire to bust his teeth out? I'm not assuming you're a violent man, but I would think the thought would cross your mind even if fighting's not your thing. Even with the second chances a friend deserves, I think five times in two months is pushing the envelope. In my mind, choosing sides here is easy: your friend is in the wrong, and your sister is not. She's expecting you to protect her from guys like this. Some curiousity questions: Did you know he's the kind of guy who cheats before he started dating your sis? Did your sis ask you if he cheats? Did you tell her he'd be faithful to her?

It's best to warn your sister about it. But, in any case, at 18 - i guess this can hardly be called a long term permanent relationship.

I think firstly, i will give him a tight slap, then ask him to get out of my sister's world immediately. This is what we called "Have a short pain rather then have a long one"

Thats sad. Be patient and try to figure out a method to show your sis all this. If possible ask your friend about him sleeping with the other girls.

I would confront your friend about this and i would also tell your sister she should know he is not faithful and shes your sister her feelings shoyuld come before your friends she is family.

You have a delicate problem here and a very sensitive situation, I think you should give her a few hints first to prepare her for this, let her know that even as he is your friend you have duty to tell her he is not as good as she think, give her time then tells her what you know or set it up so she discover the truth for herself.

I think you should tell your sister about the fact that he doesn't love him.You can also show his attitude towards girls by taking her with you but in disguise so that you don't loose your best friend.I think that should be the end of the problem.

As they say "Blood is thicker than water" It's your blood, or sister you are talking about here, would you want her to end up with a man who cheats? If he "that cheater" never mind you seeing all what he is doing, do you think he consider you as a friend? and have no sensitivity that your are the brother of the girl he is dating? Tell her, it will break her heart if she find out you already knew what is going on.

I don't know if this is the right thing to do but I would tell my sister. I have two sisters and if anyone disrespected her like that I would tell her, no one plays wth her like that. Now whether she believes me or not or whether they stay together or not is a different story. I just know what I would do if it was my sister.

c mon man .... this dude is banging your sister .... then going down the street to bang someone else ... and hes acting like he dont give a sh*t.... does your sisters happiness not matter.... shes in love with him.... this guy is gone set the bar!!! be the one that shell NEVER get over .... hes gonna be the one that ruins all the rest of her relationships!!!! you have a chance to do something....

First of nice name slappynuttz... Second, the fact that you have to post this tells me a lot about you. There is no way you should have to post this here to get help on what you should do. Family comes first. You don't let someone hurt your sister like that. Step up, be a man and protect her.

I think your sister is going to find out about this regardless of whether you tell her. When she finds out that you knew already, you are gonna be in big trouble! Not just with her but the rest of the family. You should talk to your friend and let him know that this is not acceptable, he has put you in a dreadful position. Does he really think it is ok to cheat in front of his girlfriends brother? Maybe you should think about new friends, and in future ones that are not likely to date your sister!

You need to tell your sister everything you know about your friend and what he is doing behind her back. If you really love your sister and care for her, you will tell her. If she falls more in love with him, and finds out for herself later on, she will be more hurt then if you were to tell her. And she will wonder why you didnt tell her a long time ago when you knew he was cheating on her. Just sit her down and tell her nicely.

your sister's boyfriend is so crazy.but they really loved each other .you'd better tell your sister this thing directly. but you can give her some suggestion when you are chatting .you assume that her boyfriend did so , what will you do?

If i were you, I would tell my sister. I won't tolerate my friend because in the end, he is hurting someone and especially that that someone is your sister. After telling my sister, I would help her find ways to catch him in the act about this cheating thing. That way, she won't say you are just trying to hurt their relationship. and why won't you talk to your best friend? he's your best friend anyway..