Mopsey, The man isn't happy w/himself. Look at the contacts. He's trying to feel young again and wants to try something different to see if that will make him feel better. He's going to go through all the "teen" trends before it's over with. Yes, some of what he's doing could be considered cycling. But what I see the most is the anger/replay and some depression. He can bounce around in all of these and a little bit of withdrawal too until he finally hits the bad depression. He's stressing and it's not good for him either.
As for your son, well...your h made that mess and now he has to figure out how to fix it. No one can force your son to speak to him. This is one of the consequences of his actions and it's going to take a very long hot summer for this one to thaw completely out.
I hope your daughter enjoyed her special day. I'm also glad your "older boy" came over and worked on the driveway, even though it may not have needed it. He still feels the need to help out whenever he can. It's guilt at its finest.
You will need to learn to step back and just observe. The mood swings change on a dime and give you a penny back. They are all over the place, i.e., just like a ping pong ball. It's not you at all. It's all about him. He's totally operating on emotions and we know how rational it is to have emotions controlling everything.
Mopsey, you are doing great. I just hope that your son finds an outlet for his anger and soon.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.