DNF is the sort of game I would never want my gf, sister or mother to ever see my playing.  It is a vile disturbing and downright creepy representation of women, treating them as absolutely nothing but objects.
 
Its not just the sexual inuendo and nudity, their is an entire level where you are walking around listening to women cry and moan because they've been RAPED and IMPREGNATEDrepeatedly by aliens and upon "giving birth" they explode in to chunks and the alien babies fly out of them.   Some of the lines the women say in this area are fucked up, its like listening to drunken teenage girls talk about how they were taken advantage of by sick perverts or some shit.
 
It was god damn fucked up, and if you watch GB's quicklook you can see how god damn fucked up it is.  The worst part is your playing as a guy who just laughs at this shit and then it fucking hits you, the guys who made this game thought this crap would be funny.

The chick I'm sleeping with hates shit like this, so I have to play when she's at work or taking a shit or something...that's if I'd want to play this game. I don't.

All girls are different, just like all men are different.

You should talk to her about the game first and ask her if she'd be into that kind of stuff.

@Wolverine said:

@henrik_zwomp said:

How much nudity, sex etc is this in this game? I don't want her to thinks I only bought the game because it has babes and nudity in it. And I really don't want her to start complaining a lot about the types of games I'm playing.

What is she your mother? If I felt uncomfortable doing something as meaningless as playing Duke Nukem in front of the girl I'm dating I wouldn't be dating here.

Spoken like someone who doesn't actually have a girlfriend.  

@Lazyaza: Oh man all of this is new and exciting!  Wait... no its not... because its the SAME THING that was in Duke Nukem 3D.  

Sounds like you are dating your mom, so... congrats on that...
 
As for the question, would your mom find Duke funny? If you don't think she would find him funny, then she won't be amused by the game either, the game is just Duke being Duke at, on, around, with, against, and inside things.

Me and my wife both like Duke Nukem. So, She's totally cool with it.

Its a mans game son.

@henrik_zwomp: If you both live in a trailer park and have a zillion badass tattos all over plus a shitload of fucking beer around to fuck around

FUCK YEA YOU CAN!

Play the game you pussy.