Hi Crazyguy. I can sympathize with your predicament. This is a dangerous situation, and I hope you can "nip it in the bud."
I am certainly not holding myself out as any sort of example, but this is what worked for me:
(Bear in mind, I was "in" at the time and usually attended meetings when I was in town, but was mostly going through the motions and almost never went in "service." I couldn't force myself to try to teach others something I didn't truly believe myself. I was also open and occasionally vocal about things about the organization that bothered me. That included some outright skepticism about certain of the more "iffy" doctrines, interpretations, and policies.)
When my son was around 12 or 13, I was working away from home about every other week or so. My wife and a "brother" from the congregation (who considered himself my best friend) took it upon themselves to indoctrinate him into getting baptized. They "studied" with him behind my back and would tell him I wasn't doing right and he had to help me so I wouldn't be destroyed at Armageddon. One night he came to me in tears, asking why I wasn't serving "the big J" and saying he didn't want me to be destroyed. It broke my heart, just as his little heart was breaking.
We had a long talk about things and I tried to comfort him that I wasn't doing anything bad and I just had some problems with the organization (not "J-dog" himself) and that I didn't feel right putting on a show just because of what others might think. He calmed down and became his normal happy and loving self again. The crisis was averted, but I knew I had to take action.
I immediately put my foot down, and hard! Under no circumstances was anyone other than his mother to "study" with him. When I was away, he was to obey his mother and go to the meetings with her, out of respect for her feelings as his mother, until he was 18. But he could not be compelled to go in "service." And under no circumstances whatsoever could he be baptized before he was 18. I absolutely forbade it, under threat of immediate divorce and full court press to get 100% custody. And I could have done it, too. There are circumstances not discussed here that would have practically guaranteed it. Most importantly, his mother knew I meant business, so she backed off.
He dutifully went with her to the meetings until his 18th birthday. That was his last meeting, and mine as well. That was 15 years ago, and he is now a happy and successful adult. He loves his mom and sees her often (she and I have lived apart for the last 10 years), but she has learned the quickest way to put him off is to try to push more religious nonsense down his throat. He has had more than enough.
Crazyguy, PLEASE play the "headship card," or whatever else will work, and make sure no outsider "studies" with your son behind your back. And forbid him to get baptized until he is at least 18 and knows what he's doing. I can almost guarantee he'll love you for it in the end. He'll know you stood up for him and kept him from making a terrible mistake when he didn't have all the facts and was too young to understand the lifelong ramifications.
Good luck...