"Do you think it's stupid? [...] To fall in love." (2.1.53, 2.1.55)
This is a question Perry asks his dad, wondering if it's silly to fall in love when the end of the world is going on. Has this kid never seen a movie, like, ever? Love happens when you least expect it, kid, and it can happen at any time.
"If I kissed you, would I get... you know... converted?" (2.2.95)
Okay, while R believes that love runs more than skin deep, Julie is more of a looks kind of girl. If R looks like an extra from The Walking Dead, she probably wouldn't be eager to swap spit. Good thing he looks like this. Yeah, not too shabby for a dead guy.
I pull Julie into me and kiss her. (2.8.178)
That's right: "kiss her" not "eat her brain." So is the moral of Warm Bodies that a guy can change?