I’ll be honest here - I’ve been seeing him anyway.
I know I’ll get shouted down for this, so have N/C for this post, but when I first heard it could be 12 weeks of isolation etc and that we were still able to go to shops and go to work if we couldn’t work from home, I decided that I wasn’t going to be without him for 12 weeks, when we could both legitimately be seeing each other at the shop or at work. We’re both working from home as it happens, so no contact with the outside world except shopping.
When we were advised that couples should move in together for lockdown I considered it, but he has 3 DCs and so do I, both the primary parent, so we can’t live together anyway, due to needing such a big house! Cramming 8 of us into a 4 bed house for weeks on end makes no sense, as his DCs would still see their mum and we’d all just see each other, so nobody would be any better off.
When his DCs are with their mum once a week, he comes over to mine and we spend a night together. It’s keeping us both sane and happy, gives my DCs the chance to see him, as they don’t see their own dad, and it means his ex can hang out with his DCs at their house without him there.
I don’t see why the alternative (him spending time with his ex and not me - and my kids spending time with their dad and not him) would be acceptable when our arrangement isn’t.
So anyone who doesn’t like it can fuck off! We’ve been together 8 years and are just as committed as a married couple would be, we just maintain two homes for the sake of our respective DCs so that they can have their own space near their schools/friends.