How to ask friends to not bring their children along when visiting a newborn?

Hi guys, so perhaps a weird yet sensitive post seeking advice: if friends want to visit your newborn baby, how do you tell them to not bring their children along when visiting? The issue I have is that the friend's kids (a 5yr old and a 3.5 yr and) are extremely badly behaved and disrespectful and their parents are fully aware and accepting of this behavior. Whenever I don't want them (the kids) to do something in my home, I'll tell them to stop it in front of their parents. The kids completely ignore me and their mother just laughs about it. Case in point: a few weeks ago, the 5yr old boy comes to the side of the couch where I'm sitting (I'm heavily pregnant) and starts vigorously jumping. I ask him to stop and sit down, he looks at his mother, shakes his head indicating he won't stop, and continues to jump on my couch. His mother laughs and does nothing. There are other despicable things that this 5yr boy does as well... He recently tried to stick his had in my shirt when we visited them, on a more recent occasion he stripped naked in my home the last time they visited us then sat on my sofa and started playing with his penis. Again, all this was done in the presence of his mother who again just laughed it off and did nothing to stop or correct that behavior. It's gotten to the point where it really makes my uneasy with having him around me - let alone anywhere close to my baby. His parents stated that they want to visit us after the baby is here and I don't want to ruin the friendship. How do I ask them to not bring their children without hurting the parents' feelings?