If he has a girlfriend you should keep your feelings to yourself. I might cause a lot of problems.
In a friendship you should not be put under any pressure. If someone pressures you into proving friendship they are not friends.
Sorry to hear that, but you are responsible. Because you are friends I think you should split the difference or it could split the friendship (it's not worth losing a friendship over).
If you really like a girl and you two are really good friends you should try and move on because you don't want to ruin your friendship.
You don't "have to" anything-- there are no laws about friendship. But generally, it's about the Golden Rule-- treat other people like you want them to treat you. Especially your friends, because that's part of what friendship means. If you care about a person, you should be good to them in every way you can, and they should do the same for you. Otherwise, it's not really a friendship.
you should tell them how u feel they should understand
If the feelings are reciprocated, then sure. But be careful, if the relationship doesn't work out, you may lose the friendship. Ask yourself if having a relationship outweighs the friendship.
Yes, Depending on your relationship/friendship with that person.
Best Friends or Best Friends Forever or Best Friends For Life ;)
if you are risking your friendship and its a good friendship let her make a move first
It's up to you. If you feel too uncomfortable around your friend don't be friends anymore. If you feel comfortable enough to remain friends you should stay friends because if you don't keep your friendship you might not get it back later.
Never ever leave a friendship for some girl. No matter how "amazing" she is. It is wrong and it will only hurt you. Sure, you really like this girl and such, but a friendship is much MUCH more valuable. Always keep your friends with you.
Phineas and Ferb shows several examples of good friendship. It shows how close you should be with your friends, and how you should always be a positive influence in your friends' lives.