When breaking up
"In the future, we can be more cruel and decisive to each other. Don't dwell on the past as if we have never been in love, otherwise it will only be sad."
"You said yes"
"In the future, your girlfriend will ask you who your last girlfriend was? What will you say?"
"Just make it up whatever you want."
"Then what if she doesn't believe it?"
"It's okay, just forget it if you don't believe me."