Talk to them or let them work it out as brothers

I have 3 boys. Twins who are 16 and my youngest who is 14. My youngest doesn't have a whole lot of friends. He made some a month ago and invited them over today for a sleepover. My ex husband (their dad) also lives here. So my oldest don't really like hanging out with my youngest because he's the little brother. But for some reason wanted to hang out with his friends. So they came and played video games with them and stuff and ig my 14 year old was feeling left out. He was sitting by himself while everyone else and hung out and just got mad and yelled "I hate you guys! These are my friends! This was supposed to be my sleepover". And he was crying and went upstairs. 1 out of the 5 friends he invited went upstairs to check up on him and they've been up their about 30 minutes and I can here my son crying. My ex said we should give it another 30 minutes and if he doesn't come down we'll go talk to him. But I think maybe we should let them work it out themselves. Idk what do you think the right thing to do is?