[Isabo]

Discussing tattoos with beloved offspring and a couple of her friends a few years ago I was told that "if the tattoo god speaks to you, you have to listen". I think that means if a teen wants a tattoo they will get it, parental disapproval may be a plus for some.
I agree with you on the lying by ommission, but have you considered that it's a sign of their esteem for you, especially the stepdaughters? If they didn't rate you they wouldn't bother.