I had this crazy theory that Alex knew that Aron's love for Carter was never completely waters under the bridge. This is no way a explanation for him cheating on an amazing guy who treats him like a princess, but people had crazy thoughts, right?
The problem is that I think Aron will fall in love(fall more in love?) with Alex because of Carter being in this body. And since I believe Carter will also fall in love with Aron, the only explanation is Aron discovering and believing in the switch of bodies between them. Gosh, so complicated lol