I [M] had ever fantasized about my dad and my girlfriends

I don’t know why , but I have ever had this kind of dirty thoughts about my dad and my girlfriends ! When I was younger we used to play soccer together so I’ve seen him lot of time under the shower… and he’s really big ( I’ve never seen hard but I think it’s around 9/10 inch).
One of my first girlfriend was too much flirty with him , always wear short and revealing dresses in front of him , make jokes and staring a lot , once she sat on his lap “for joke”
Since I was 16 year old I’ve ever fantasized about him fucking all of my girlfriend, using them like his personal sluts, letting them blowing him every time they can. Nobody in real life know nothing about it