Wet, I do understand how you feel, but the only person you are hurting is yourself by not attending your S13's ball games. Your son is also going to be hurt and disappointed that you aren't there to cheer him on and offer him and his team support. Why allow this man's presence to ruin the time you are supporting your son?
I'm sure the area where your son is playing has plenty of places for you to sit elsewhere. I would go and not allow your wife and the om to get under your skin. She deliberately called you to make you angry so that you would either pitch a fit w/her or not go to the game. Don't give her that satisfaction. I wouldn't discuss this w/your son. Why? Because it puts him in the middle of the situation and he doesn't need to be there. He's got enough to deal w/daily.
I wouldn't deny myself the pleasure of watching my son play ball. This is his night and you, as his father, should go. Don't allow them to take away this awesome time to make happy memories for and with your son. Go and have fun. To heck w/your wife and the om.
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.