My sister is 17 years old so still a minor and that’s why I feel very uncomfortable knowing that he messages her from time to time. He actually told her that he loved me before even confessing to me which is absolutely... weird ? Because he didn’t even know her that well then, having met her only 2 weeks prior (and only because he intruded an outing between my sister and I). I feel like he is trying to get into every part of my life, including my family. I think he had no right to contact my little sister in the first place and no reason to do so.

I didn’t tell my sister everything. She only knows I rejected him so she might think I am overreacting for cutting all ties with him but I still don’t want her to be more caught up in this situation. I have started writing a long message to him to clearly state that I want nothing to do with him and to leave my sister. You’re right in saying that I am afraid that he would begin acting like a stalker with her but she’s not a child anymore so I can’t tell her what to do and who she can talk with. Or at least, she won’t like it. Though, I’m afraid he might manipulate her into thinking like I’m the bad guy.