A: Why are you so nice to me? I will hurt you..
B: It is normal to be nice to someone you care about isn't it? Why would I wanna be intentionally hurtful or cruel? I don't swear by the adage 'if I can't have u thinking of me with affection, at last you'll think of me with annoyance'. It's a little juvenile.
A: Why do you like me then?
B: For various reasons. Or would you prefer, "I don't know? You can't choose who you like."