Is it ok to kiss your bfs brother?

Complicated or not, if you are in a relationship and you kiss, sleep or just start going out with someone else to see what might happen between the two of you, that's cheating. Now, with the brother? Sister, cousin, best friend? Yes, there are some rare cases where for God knows why the girlfriend ends up marrying the brother or stuff like that and things work out, but chances of that happening are very small (specially if you're a teenager). If that was the case (of you being a teenager) you have to think of the consequences, what if it doesn't work out with the brother either? Will they be calling you names in school in front of everyone?
The greatest advice I can give is don't do to others what you wouldn't want others to do to you.
Again I don't know if you're too young or ever heard this saying, but it only means... What if your bf was kissing your sister or brother (don't know if you're gay or straight either :P)

I think we have to take many factors into consideration:
First, how old is he?
Second, what's the reason?
Third, does your boyfriend mind?
Fourth, is it accepted by the public?
Before doing that, you have to be calm and don't be eager to do that!

It depends how old your boyfriend's brother is and what was the intention behind your kiss.. If its a normal greeting, then its no issue but if intentions were wrong at that time them yes it is a cheating on your boyfriend and you need to admit that.

No, unless he's a kid, and it's just a friendly kiss on the cheek

Now is bf boy friend or best friend, I guess kissing your best friend's brother would be better then kissing your boyfriend's brother... Because if you do that then you've got serious problems.

This depends on a number of factors.
1. How old is his brother(It's ok if it's a kid)
2. If kissing is a greeting in your culture.
3. Were is the kiss being placed?

NO... Lol because first its like your kinda cheating on your bf and second your kinda cheatin on him with his brother lol unless ^^ it is just a friendly kiss on the cheek then ye its fine :P

No not at all

Is he 5 months old ? Then its okay