My ex didn't once get up in the night for baby ds, didn't once change a smelly nappy. While I gave birth, he morphed in 1950s man. 🙄We left him when ds was 2.
From that moment, he didn't have ds overnight until ds was fully toilet trained, could dress himself and use a knife & fork accurately.
Then he had him a couple of nights between xmas and new year, and one week in the summer, so maybe 9 or 10 nghts per year. I did the other 355 nights/year, including while I underwent chemo & radiotherapy.
My mum died years before and other family were not local. I remained single for the duration of ds' childhood
On the bright side I think my ds, now 18, is a kinder, happier, more confident, secure & competent young man as a result. 🙂