by jan46 » Wed Jul 04, 2012 10:18 pm
If you are over 21 then you are an adult. If the kids are yours then you are responsible for them. While it is incredibly tacky for them to have done this, there is no law against it as you were with the kids. (Had just your kids been left, without an adult, then it would have been child abandonment and that is illegal.)
What you need to do is get home and never do anything with the family again. It is entirely within your rights to cut them off from any contact with your kids. You can use this specific event as justification, saying they clearly do not have the best interests of the kids in mind and you do not want to give them any chances of hurting the kids like this again.
Return anything that you have of theirs, send them a registered letter telling them that they are no longer welcome at your home and that if they do come around, you will call the cops.