Does it matter why he has or hasn't told the kids? I don't think it does.
My H is also very teenlike in his behaviour. More so even than my teens. We share a kindle account and lately he has been downloading nothing but Frederick Forsyth books! It's pretty funny really. What next, he takes up skateboarding?
I treat my teens with compassion and love and a huge, huge dose of putting up with poor communication, surliness and slobbing about a lot. I'm trying to cultivate the same with H. My teens will grow up though, not so sure about H...