I would ask my husband why he invited people over to the house when he knew his son was sick? and why those people and their feelings were more important than the well-being and healing time of his son? and why couldn't he just tell them this was a bad time. if they invited themselves then he should have said it wasn't a good time for the kids to play. or that only the adults could come based on the instructions from the doctor.
if they were your real friends they would have understood.
if that didn't work. then i would take the kids and go to a hotel and let your husband entertain "his friends" and put up with their behaviour. if he had to, then he would stop inviting them over.
i am also curious why he left you to do the dirty work of telling them no. And I am also curious why you didn't tell them "NO", but hell no.
So what I get, is that, their feelings and how they think of you is more important than the well-being of your son. which isn't what you probably think, but definatley how you acted. because you didn't tell them no anymore than your husband did. so you ran the risk of setting the healing back on your son, did not follow doctors orders, and exposed him to a wild child, because why????
perhaps a compromise would have been for the hubbies to get together at your place and have a family event when your son was better.
frankly, if they couldn't control their son with meds or without they wouldn't be at my house period. that is not fun to me nor SAFE for anyone involved. same with the 2 year old. obviously they use it as an opportunity to let them run wild while you chase them and babysit and they do what????? and when their son does something really bad and someone gets really hurt you will wonder why you didn't say or do something before. and they will be what chagrined and sorry? to late after the fact.
sorry, i am not meaning to be rude. i just don't understand why you are asking how to handle this situation when you say you don't have a problem telling them no and obviously knew what you should have done but didn't choose to do what you knew to do and why your husband didn't support his son first. it just sounds like you are looking for an excuse to justify you or your husbands behaviour because you feel guilty giving in and not fighting about the visit. when you knew that you didn't need to have them out to begin with so that your son could heal. or you are venting about your husband and the fact that he didn't make a very good decision based on the needs of your son and putting your family first above these friends. i would suggest the problem isn't with your "friends" but with your husband.
if i had a friend who's son had surgery, i would have canceled myself and not put my friend in the position to have to choose. i would gather the kids up, pick up a get well card, a small toy, taken them a frozen lasagna, visited just long enough to drop that stuff off and let them know if they needed anything to call, and LEFT. the parents know their son has problems but gave you little thought by not canceling. and that shows that they are not really your friends. especially, if i know my son had issues and he would be around a sick child? no way.
i hope that you can resolve the situation and that your son heals nicely.
good luck,
L.