Long time lurking, first time posting so forgive me for the long post. I’m 28 and live in the UK and also what’s known in old terms as a HFA (high functioning autistic). 

I have been with my partner for 18months.living together since June 2018. SO has two daughters: SD20 and SD11. SD20 isn’t my SO bio child, he adopted when he married his ex wife. He left her two years before we got together due to her stealing his money to gamble and going out getting drunk, doing speed and being a crap mum.