It doesn't even enter my mind that I have to think of think of things to entertain my teenage stepson??
I just take care of the other kids and do my own thing.
I usually make sure I go out and leave DH and him to watch a movie or whatever on a Saturday night or I just go to bed.
Your living arrangements sound.....well to be honest, excruciating for everyone. How long until your house is built?
I think you need to disengage a little bit.