can't believe the nerve HYPOCRITES

A couple of months ago I thought we (me, my son, my daughter and my SO) may need a place to live until we could get our feet back under us financially. I lost my job and my SO was working two jobs but both were part time. Well my Mom let me know that me and my kids could come but my SO couldn't unless we are married, which we aren't. Yeah I was pissed because I've given my mother literally THOUSANDS of dollars each year. I had a business the past 10 years and would give her $1000 a month plus bought her a Ford Expedition and paid the insurance on it (she had it 4 years before totaling it). Then I let her have one of my cars to drive and if course I paid the note and insurance on that. Seriously it's more than this but you get the point. Anyway I'm not leaving my SO and we plan to marry as soon as my divorce is finalized (maybe 60 days out, but separated from ex for 2+ years).  Now I have a new job but it's in a different state and I still have my house in the city where my mother lives. Last night my mother has the nerve ask me if my son (age 26) and his can come live in my house. Excuse me but they aren't married either. Oh and they want the Master bedroom 😳. My SO and I Plan to spend half the week here and the rest of the time there, so it's not like we won't be at the house ever. Why is it okay for them to "shack up" at my house but not for her to allow us to stay at her house.