My girlfriend is so turned on by my big cock that she doesn't even ask me to stop

My girlfriend is a real 18y.o hottie with a big ass that's always begging for some hardcore action. I've got a big cock that she can't get enough of, and she never even asks me to stop. She's always on her knees, ready to give me a blowjob whenever I want it. It's not just about the size of my cock, it's the way she sucks it that really turns her on. She's an amateur babe who loves to ride my cock in cowgirl position, or get fucked doggystyle from behind. Sometimes, when we're getting down and dirty, my friend will come over to watch. He can't resist the sight of my girlfriend getting fucked by my big cock. She's a real 18years old teen with a big ass who loves to suck cock and get fucked hard.