I'm very happy to hear that your son is with you 24/7.
The story you described from your wife is worrisome. True, there are 2 sides to every story (possibly 3 in this case). What has your son said about it? Teenage boys can certainly have a short fuse, but this sounds like more investigating would be appropriate.
How is he doing in school? Is there a counselor at school that either of you speak with?
The "just kidding" comment during the toenail clipping is teenage boy lingo for "Oh, I just got caught doing something I shouldn't? Then I must have been kidding" IMHO
Hang in there! Cristy
A Divorce Busting Coach can help you save your marriage, even when your spouse wants out.
Email virginia@divorcebusting.com or 303-444-7004 for more information or to get started right away.