Hey, don't let him! Please, it is just wasting time and happiness. I know how easy it can be: have an argument, feel down, shut yourself from the others.
I didn't use to have a single friend here, apart from my DH. I got introduced and somehow accepted into his group of friends, but they were never my friends. To give you an example or two: their idea of meeting up is a dinner in a restaurant, no children. My idea of meeting up is everybody brings a pot of something and we eat while the kids run a riot. I enjoy reading, I can get quite enthusiastic about a book, and trying to discuss this with my DH's friends was met with slight smirks:glad you have time to read, we don't. I don't honestly know WHAT they enjoy doing, in 18 years I am yet to find a common point. But I am going along to these meets and make polite conversation and I do care about them and saw their kids grow up, but that's about it, really.
So I used to get quite lonely. So then I had my own group of friends, much more up my street, joined a book club, a swimming club, we go to art galleries, doesn't matter, we have things in common and we enjoy each other's company and have done so for years. My DH refused to join in initially, so we led parallel lives for a while. I would make an effort every time his friends were involved, I was the pretty, funny, easy going wife of X (my DH's words, not mine), my DH would be the morose snubby husband of Dilidali (again, his words, not mine) because he didn't know my friends from Adam, didn't grow up with them and quite frankly, he had friends, didn't need new ones.
In the end he had to go with what made me happy, I was very patient, but also never tried to either force my friends on him, or let him force his friends on me. I would quite swiftly sort out clashes with a simple: that's quite alright, I'll go on my own to X and you go to Y, see you at home later on. We'd meet up afterwards and fill each other in over a cup of tea at 1am.
What I am saying is in an ideal world these things would come naturally. In my world that was b**y hard work and had to be carefully orchestrated. We now have a good social life that involves both of us most of the time, also we have times when we socialise on our own. But it wasn't always a given.
Things I wish my mother taught me, eh?