(it's No) Sin Puns

I came in from having a cigarette and while closing the cumbersome sliding glass door I remarked, "Man that door is heavy!"

"I know," she says, "sometimes it pushes me back."

"That's terrible! Has it committed any other crimes against you?" I asked.

"No, but we should still sue it for everything it has though!" she said.

I grinned at her and offered, "It would probably just say it was framed."

She let out a quiet groan and flippantly said, "You're funny"

Edit: words

Girlfriend: Have you heard of Sin city?

Me: Yeah, the movie?

Girlfriend: Nope, have you heard of Den city?

Me: No stop, I won't let you do this.

Girlfriend: It's mass over volume.

I think I'm in trouble for not letting her finish the joke

Initially inspired by a joke I heard elsewhere on the Internet but I took it a step farther. Hint: there are several hidden puns (at least 6)

Dear Algebra, Stop asking me to find your X. As to the reason she left, we'll never know Y. She probably never fancied your green bra. Maybe it's a sin that she wants a distant relationship. But have no fear, as she spans higher dimensions for true love, she'll look far and wide, for she lives on the edge. She'll soon realize that she's not so significant after all.