I'm feeling bad for my hubby tonight... his one nephew (he's closest to this nephew and this sister…

I'm feeling bad for my hubby tonight... his one nephew (he's closest to this nephew and this sister of his) is acting like a complete brat... my sisters in law and my husband were planning a trip out last night to see a cousin of theirs band, along with spouses... my sister in law said that her son (said nephew) could babysit our kids because he didn't need to be at his girlfriends yet again half the night (she is 16 our nephew is 18 will be 19 in April)... well he threw a fit when my husband asked him if he would (nephew was helping my husband at his new shop)... his nephew got all huffy and puffy and said "fine I'll just break up with my girlfriend" my husband told him he didn't have to watch the kids it wasn't a big deal.... the nephew then decided that he was going to go home, pack all his stuff, and move out (we think he had been planning this for awhile)... our nephew is a type 1 diabetic, who doesn't really follow his diet, blows all the money he makes as soon as he gets it on ridiculous things, and has recently been putting his mom thru hell for lack of a better word lying and such... my husband is worried about his sister (she is also diabetic) because she is so upset over this whole thing and her son doesn't even seem to care... I feel bad for my husband and sister in law that they are going thru this (he is almost like a son to my husband)... my husband said he better not show his face around here for awhile (actually he said ever again).... I just don't know what to do mamas