My Boyfriend asked out my best friend before we were together. After I came to know I didn't think much of it but now I'm suspicious.?

Of what?

Dating is for practice, so don't be so possessive. If he chose to date a friend of yours first, but is now with you, that's his right.

You don't own him - don't ever forget that.

What he decides to do is his right, as you have yours.

If you don't have his full attention, that's a subject for a discussion - but don't get jealous because he once dated a friend - you don't actually think he came off some planet where guys only date you, did you?

Don't ever forget, you're dating. You're not married.

He asked her out.... did she even go? That was then, this is now.

Right now he's YOUR boyfriend. I don't see why you're suspicious?

I'm sure he asked a lot of other girls out before you but unless there is something suspicious going on, forget it.

No, that would be being paranoid to be concerned. You are young. Enjoy what you have, knowing that most likely you will have several more boyfriends before you find "the one".