So I caught my dad with my GF, what should I do?!?!

I've had my GF for 2 years now (practically lives with me) - small white, petite thang, cooks for me, always been good to me.

I go away on holiday for a week, come back and something just doesn't seem right. I asked my Father if he had seen anything happen with my GF and he acts clueless.

So fast forward to 3 weeks later... I'm coming home from work when BAM clear as day, right in my Kitchen I catch my Father red handed with his meat in my GF.

I was pissed, told him to get his meat out of GF and GTFO, needless to say my GF got turned off. I just couldn't get over it and that night kicked my GF to the curb.

Now it's been 2 weeks since the incident and that I've been without my GF and about 10 minutes ago my Father had the audacity to ask my how my GF has been, when he's the damn reason we ain't together no more.

Should I get off the computer and start swinging at him?

OR

Pack my stuff and be on my way.

Here's pics of my GF for you guys as I know you'll ask.
http://img229.imageshack.us/i/95a9ac6fe2...