Hi Daisy
I don’t live with my partner and could list lots of nice things I do alone in the evenings but I think you are looking for things that people do together, specifically at home (as it sounds like childcare is tough for you).
When together at home, we cook. It’s nice to plan what we’re going to have, shop for ingredients, share some wine while making it and potter about the kitchen. We can spend hours at the table afterwards talking and eating.
We have some Netflix series we both like and enjoy cosy, rainy Sundays in comfy clothes, under a blanket on the couch.
He trained in massage years ago (I know, lucky me!) and so one of us might buy a nice new oil, candles and we trade massages.
Technically, his are better than mine
These massages usually end in other.. activities. And that’s nice too!
This is very cheesy and I am probably unlikely to admit it in real life (!) but we read to each other
We both studied literature at uni years ago and although our jobs are in completely unrelated fields now, we still love books, reading, poetry etc. So sometimes we have a book that we’re kind of reading together.
I love yoga and do a lot of Home classes through YogaGlo. He doesn’t want to join in for a proper full on Vinyasa Flow class! But is quite physically active and so will do a few minutes of geveral hatha/ stretchy yoga with me. Or will watch with amusement and encouragement if I’m trying to get into a headstand or some other funny pose! 
We often walk around the village (don’t know how this works with for you with kids or your location).
Hope this helps with some ideas!