dude, this is a perfect scenario...he already knows you, and hangs out with you, so he clearly thinks you are a decent guy.
I'm pretty sure every father is happy with his daughter going out with a decent guy (cos you wont stop her going out with guys, atleast he knows you're decent and not a tit!)
so speak to him...her father already likes you...if he's okay with it(which he should be, unless he's like a really paranoid dad, and expectes her never to go out with anyone, ever) then go for it...if he dissapporves, its your call.
Aschleman is right tho...once the parents like you, you're in a great position...especially if they know you well...then even if you do break up, they'll always wish that their daughter was with you, instead of...
Just talk to him about it...tell him how you feel, not how hot his daughter is...and he should be cool with it
[FONT=Century Gothic]Hope is when we feel the pain that makes us try again[/FONT]