The questions I'm asking are ones I imagine she feels she should have asked before she married me. The necessary implication of framing the matter this way, of course, is that I was an unsuitable husband and the failure of the marriage was my fault. I'm content to assume both things for the sake of this discussion, and indeed for most other purposes.
Something that I think she would, in hindsight, have viewed as a red flag was my distinct shortage of friends before we got married. The picture I gave when we were courting may have been unintentionally misleading. A good number of the people I thought were friends turned out simply to be "coworkers" or "blokes I went to uni with". I did not know there was a difference. If she had had a clear picture, I expect she would have been less willing to marry me. I do not think I would have blamed her.
I have proved amazingly bad at hanging on to friends over the years. As of 2007-2011 I was only in the loosest contact with people from my school or university days (we might catch up once a year). I worked too hard in my first decade as a lawyer to have time for a social life even if I had desired one, which I didn't. This meant that our marriage had a shackle from the start: I well recall The Ex saying sadly how she missed having a social life like that of other young couples. She might fairly have added that it'd be nice to be with someone who could be at a social event without looking like his wisdom teeth were being extracted without anaesthetic.
Based on this experience, I offer you ten things to consider before getting involved with a man with no friends.
First: ask yourself how long they've been solitary for? The reality is, if it's been a few years, the habits of living alone and thinking for one are going to be well-ingrained. You'll have only limited leverage by threatening to leave. After the shock and sense of betrayal has worn off, the response is likely to be "ok".
Second: Your wedding day will be out of kilter. You'll have bridesmaids and a maid of honour and the like. He'll have a best man he barely knows and groomsmen hired through Airtasker. If that's not a good omen I don't know what is.
Third: Fundamentally, most of his social contacts are transactional. Going to someone's house to help them fill in a claim form or to borrow a lawnmower is a perfectly normal thing to do. Going to someone's house to drink tea and make small talk will seem as absurd as tattooing "buffoon" on one's head. Suggesting it will have him look at you like you're speaking Norwegian.
Fourth: You'll be socialising alone a lot of the time. I recall once waiting a long time outside the Ex's work and declining her invitiations to come and drink at the Prince Patrick Hotel on a Friday evening because by that stage of the week I couldn't face another person. She felt guilty about that. I had a book to read and didn't mind in the slightest.
Fifth: Sometimes he'll be no fun at all. I recall a lunches, dinners, pub trips and one football game where I was counting the time till I could leave and (at one lunch) became more and more unpleasant and shocking because it was the only entertainment on offer. We weren't invited back.
Sixth: Despite anything Google will tell you, don't try and treat his nature as a problem to be fixed. Doing the things recommended here will be really. fucking. annoying. I speak from experience. Fish are not made to run. Turtles are not made to fly. Some people are not meant to be sociable.
Seventh: The place you live is neither yours nor his, but belongs to both of you. So if he's driving home from work on a Friday, and you text him to say a half dozen friends (and remember, they're basically your friends) are there and can he get a couple of buckets of KFC, don't expect him to be happy about it. From his perspective, it feels like a non-violent home invasion.
Eighth: You'll probably fight after any social gatherings you host. Because he doesn't much like talking, and because sulking is childish, he keeps busy. This means he'll spend much of the time mixing drinks, cleaning up, washing dishes, plating up food and so on. You won't pick up on this, because you have a social nature and will be enjoying the gathering. At some level, your friends will see you as the Host and him as The Help. He'll pick up on this. And he'll resent the fuck out of it.
Ninth: The relationship won't last forever. You're too different. Perhaps you'll leave. Perhaps he will. It won't matter. Either way, the final word will go to Edgar Allen Poe -
"Leave my loneliness unbroken!—quit the bust above my door! / Take thy beak from out my heart, and take thy form from off my door!"
Tenth: On the bright side, when you break up, you'll get to keep all the friends. He'll be just fine with that.
What do you think are the things to know about being with a loner?