A man I'm becoming involved with. I usually see too tight a mother/son bond as a bit of a red flag but this seems OK, if unusual.
Not my story so I've changed some details but:
Mum left with OM when friend and his DBro were 8 & 10. She lived overseas until that relationship failed and friend didn't see mother again until he was 21.
Dad at the time was considered something of a hero, caring for these two DC on his own, but what actually happened was he took a job where he worked away most weeks and friend was left looking after dbro 5 days nights a week from 12yo.
Today friend is in his 50s and seems very close to both parents, having taken on a parental role towards them. E.g. mum's return flights cancelled on recent holiday and he sorted it all out for her. He'll go and water Dad's garden most evenings.
This doesn't seem to interfere too much with his daily life, He'll pop in for 20 mins here and there rather than give over whole weekends to it, but especially mother it all seems a bit strange to me. Although also lovely that he seems so decent and willing to help.
They're not young now, but both fit and active still. I'd say he sees one or other of them practically every day, although not for very long, will pop in on his way to or from work.