If you have ever fucked your wife soon after she gave birth (within weeks) then it was a pity fuck for sure. If she was breast feeding then again, it was prob a pity fuck since her estrogen was lacking. Apparently as long as they are breast feeding estrogen is low which is responsible for the lining of the vagina = raw pussy = sex hurts. This is my world right now, since my wife is getting back in shape, looks hot as hell tits bigger than a blimp and i'm lucky to get a pity fuk and i know it's going to hurt her.
There are other pity fucks but i don't feel like elaborating.
When I was 20 I went down on a girl, even though I didn't really want to, I didn't like her, but she kept asking. Then she offered to cook for me, and since I was hungry I accepted.