I Sleep Over At My Friends House So I Can Suck Off Her Dad

He usually waits for everyone to go to sleep, he walks past her room and slightly opens the door and then goes straight to the living room. When I see the door open that's my cue to follow him into the living room. I go and get down on my knees straight away and suck him off until he cuts in my mouth, sometimes he cums on my face, sometimes he fucks my mouth but never more than oral and he never does anything back to me. Once he's finished he gets up and goes back to bed with his wife and never speaks a single word to me during the whole thing. I feel so used but I can't stop I keep finding excuses to have a "sleep over".