Dustin, being 2000 miles away from his girlfriend, is hormonal and desperate. When he accidentally finds out that Steve is extremely susceptible to hypnosis, he gives into temptation and uses Steve to get some relief. I'm imagining he orders Steve to give him a blow job, but feel free to take it further if you wish. When Dustin breaks the hypnosis, Steve doesn't remember a thing.

Dustin ends up doing it again, and again, and again. Up to you if Steve finds out, or if he remains blissfully unaware the entire time.