Frienemy

A stranger that has the potential to become either a friend or an enemy

Ex. 1
A: Hey!
Stranger: Uh...hi? Why are you talking to me? Please stop. Go away...you're creepy.
^A frienemy gone bad

Ex. 2
A: Hey!
Stranger: HI! OMG! You're so awesome! Let's go be friends!<3