well it depends if she istraditional or not. if she wants to wait to marriage then don't try to convince her. if not then try to serenade her. to do that do sweet romantic things if she i a romantic girl.
Just be yourself.
Don't lie to her.
give her flowers
compliment her boobs
Tell her mom
tell her you will be safe and fine
you can't. maybe he is happy the way he is.
by letting her do her own thing
Tell him, "If I had feelings for him, I'd be his girlfriend.
YOU DON'T!!!! She has her own choice you dont force her!!!!!!!!!!!
tell her you have a foot fetish or ask for her shoes
why would you want to it's her tattoo leave it alone