My biological father signed his rights to me away when I was five, but my mother always allowed him to see me a few times a year at his request. I'm not close with him, but I do still meet up with him once every few months even now at 24 years old. My problem is that he has another daughter who is 14 that he is trying to force me to have a relationship with. I've been around her a handful of times since her birth but I do not know her and do not think of her as my sister. He does not respect that I do not want contact with her and does things like give her my number without asking me and having her contact me randomly which is super uncomfortable. He nags me about having a relationship with her whenever I see him, and at one point he even brought her to my grandmother(my mom's mom)'s funeral and she said something about reuniting even though she was never my sister and I had to hide how angry I was because he should not have brought here there at all. I have asked him repeatedly to stop trying to force two strangers who are 10 years apart in age to suddenly be sisters, but he doesnt listen. I was not raised with this girl, I do not know her, and I feel extremely uncomfortable when she contacts me because he has it in her head that I'm her big sister and want a relationship with her, when I don't. My life is just beginning, it's super hectic, and I already have 5 siblings that I grew up with that I barely even have time for. How do I get him to stop trying to force this?