Odd question I’m sure.
My stepdad married my mom when I was 15. He has never naturalized as an American citizen, but I was able to sponsor him for his green card since US law considers him my parent.
Is there a way I can get UK citizenship from him? I’m not legally adopted, but he’s been my stepdad since I was 15, over a decade now.
You’re not going to get UK citizenship from that relationship, but you may be able to qualify for a family visa as the child of a UK citizen. However, not being legally adopted is likely an obstacle.