I always tell kids - within earshot of parents - when you are in my house, you are my kid...
now I would never lay a hand on any body else's kids but if they are acting like nit-wits then they hear about it....
I flat out told one woman I did not want her grandson in my house ever again - he's the kind that snoops and sneaks and peeks to see if you are watching...
and as others have said - re-examine the relationship - is it your house or bf's?, who pays the bills?,.....
can't tell me that some other "adult" in the house didn't know some of that was going on...
are these kids going to be like the little '*&it' that burned that other grand-daughter's quilt..?
better alone than surrounded by trash...
MOO-YMMV