yes, because that's still your boyfriend... try to fix things.
Well i think you should just let it play out and if he cares about you he will not cheat on you or anything bad like that.
Unless the ex boyfriend was part of the problem then no, you should not involve your ex boyfriend while resolving your problems with your friend.
no and you should avoid having an argument again, if you really like him then go apologize!
yeah you should because you have to sort it out and tell your own story/view/opinion, if you dont, you guys would brake up becoming enemies and not talk to each other. it would be very awkward
just call him one last time and giv him a chance to forgive. if not dump him!
I am sure there is more to this story. I can only comment on what you stated in your question. If you boyfriend walked away from you simply because he had an argument with your sister then he doesn't love you that much. After all, what do you have to do with the argument between them. Either you sided with your sister or she accused him of not treating you right and you didn't side with him or said nothing. Perhaps you should let this fish get away. If he can walk out on you so easily and not be a big enough man to come to some amicable agreement with your sister then it's best you let him move on.
If your boyfriend is always busy, at least give it an attempt to try to hang-out/spend time together that way if an argument starts about it he can't say "well you didn't try." If you can never see him, then why go out?
No because whats a the point of having a boyfriend
Kate Keller drove out Helen's boyfriend because she thought Helen should not get married because of blindness.
Yes, because if you get it, you could die.
you should tell your boyfriend if he really likes you if he says yes tell him if he believes you or other people that started the rumor because your boyfriend should only believe you not other people
its probably because she loves someone else or she found out something about her boyfriend she should not have known