Because...

BB: Awhh... you should ask him out!
MN: Hahaha... nahhh... I wouldn't wanna do that.
BB: Why not?!
MN: Because...
BB: Becauseeee?
MN: Because we're just good friends.
BB: That's not a good reason!
MN: He's my best friend! And I know I'm just too busy for a relationship right now, so if I asked him out now I know it would fail... I just don't want it to be like that...
BB: Awhhh!!! You LOVE him!
MN: What?! That's not what I said!
BB: Hahaha, it's what you meant!
MN: Whatever, you're crazy. (: