Since I don't have kids I can't really imagine how hard that conversation was for you. But I applaud how you handled it and I am sure your son will appreciate it even more as he gets older.
I feel you on the continued lying. WTF? xBF has a similar problem, even when I've explained that I've had enough and it isn't going to do him any good. Sigh. Personally I'm glad you called him on it, maintain those boundaries.
Sending good thoughts your way for a better day tomorrow!
If you love somebody, set them free. http://tinyurl.com/2empx2g