How am i going to take care of my cousin without going crazy with that rich ass he has?

My cousin is going to stay at my house for a season to finish an internship for the company where he works. i promised his parents that i would take care of him but he is finding it very difficult. he is a crazy man in his twenties who keeps chasing me. i try to ignore him but when he stands in front of me today with his ass in the air and starts jerking off as if he were alone i get so hot that i also end up with my cock out. how rich when i notice how his little ass opens up when i fuck him if i control.