Once Alina is asleep, he gets the part started by lightly touching her cooch above her panties and then her perky braless tits. His touches gradually get bolder and hotter until he has pulled his stepsister's panties off and has free rein to finger her landing strip fuck hole. When even that doesn't wake Alina up, Damon decides to go full throttle and pulls his dick out.
Damon's long slow strokes wake his stepsister gradually. She comes to with a smile on her face, but doesn't let him know that she's up right away. When she senses that Damon is about to pull away, Alina finally gives up the pretense of sleep and becomes an active participant in the fun.