When is right to call your boyfriend "baby"?

Personally. I wouldn't ever want to be called baby. Maybe some guys do? Just be careful what you call him, it may be seen as an insult.

ASK! He might like a cute nick-name like baby or something, even if you are shy like me.You should ask him. The probable embarrassment will pay off.

for this sort of stuff I think it is ok for the guy to make the first move and call you "baby".
but if you both are shy and confused, just wait till you feel comfortable.