Babies+coronavirus+step child traveling

So my bf and I have a 4 month old and a 16 month old. He also has a 9 year old who we have on weekends at my house.

The 9 year old just flew to NJ for 2 weeks for leisure to see a cousin.

With Covid and having babies I told him she can not be here and if he’s around her he can’t come around the babies for 14 days after she gets back..

I told him this and he said “ok”

My parents watch the babies 2 days a week so we can work. My dad is high risk and my sister has lung cancer and is living there. I can not risk my family due to them wanting to let her travel for fun...

Today her mom texted him asking if he’s keeping her until Sunday (flew in today). He told her yes.....

Her mom hasn’t had her in 3 weeks, she can keep her for 2 weeks

And no he doesn’t pay bills at my house..

*******

Well he went to his grandmas w all 3 people that just traveled, so I told him we will see him in 14 days..