The babysitter had her boyfriend over and didn't clear it with you.
What to do: Give her a warning, or let her go
Let your sitter know that if she plans to have a guest, she needs to ask your permission and introduce the friend to you first, says Douglas. Breaking the rule -- even once -- shows she's not mature enough to take care of your kids. It's generally a bad idea to allow a boyfriend to visit: Even if the teenager can be trusted to keep things G-rated in front of your kids, he'll inevitably distract your sitter. On the other hand, if the co-sitter is a responsible friend, it can be like getting two caregivers for the price of one.