So here's my theory on why Morgan calls Reid 'Pretty Boy.' working just with what we seen screen and assuming no relationship between them, why would he call him that? It's not sarcastic, in Reid's most frightened and vulnerable moment he calls him that. I think he doesn't because Reid has full confidence in his brain. He's always admired and appreciated for that. But he's socially awkward. Beautiful women have hit on him (they aren't blind and stupid after all) but it doesn't seem to have registered with him that he's physically very attractive.
It can't have helped that he was probably out of undergraduate school before he even fully entered puberty. He had to deal with his dysfunctional home. He had to time or opportunity to really explore any kinds of relationships. We don't even know for sure his sexual orientation, Im not convinced he's sure himself. So getting back to the point, I think Morgan does it to,remind Reid that he's more than just a brain.
It can't have helped that he was probably out of undergraduate school before he even fully entered puberty. He had to deal with his dysfunctional home. He had to time or opportunity to really explore any kinds of relationships. We don't even know for sure his sexual orientation, Im not convinced he's sure himself. So getting back to the point, I think Morgan does it to,remind Reid that he's more than just a brain.