Does Alex know about all of this? It sounds to me like your son knows Marcia is cheating on Alex, and has fallen into the role of the "secret lover." He's willing to be played now because he's hoping to get to date her exclusively in the future. But Alex has had her to himself in the past, and it would be very unusual for him to be cool with the situation as it is.
I'd have a chat with Marcia, and possibly a chat (threatened or real) with Alex.
|