So my boyfriend and I have Been dating for over a year now and my younger sister who is now 15 (we're both 22) has I guess you can say a little girl crush on him. Which is fine she's boy crazy I don't think too much into it. Well recently he moved in with us, my boyfriend, and it seems as though he prefers to hang with her and he has more fun with her. I honestly feel like an idiot but their relationship kind of weirds me out. At first I just thought oh well he is just treating like a sister cool well apparently when I'm at work he hangs out in her room. And even when I'm home he'll just go and talk to her and ignore me. And even compliments her clothes. Like I can't help to find it weird. I mean I def wouldn't just hang out with his younger brother and his friends. Maybe I'm being dumb because I just don't see myself being that close to his younger brother? Idk any thoughts

Tell him your concerns, see his reaction and write back to us. He might just be friendly like that, or he might like her, in that case, you would need to kick him the hell out.

Before you say or do anything, make sure you are not having issues. You can talk to your boyfriend without accusing him of anything. Unless you have facts, don't over react out of fear, or jealousy.

Well when he first told me he was hanging with her in her room, I kind of made this face kind of like "okayy" and he asked "is that wrong?" and I answered with "well did my parents think it was weird?" and he said "well no they didnt say anything about it" and I said "well i would just think that, that is weird. since you are 22 and she is underage.." and I said "well i mean just what would your mom think if i was just hanging with your 16 yr old brother in his room". And he kind of just said yeah I guess and that was pretty much the end of the conversation. Idk does that help a little more with this situation?

Personally I find it odd for him to be hanging out in her room.

Not only because she's a minor but because a bedroom really is an intimate space, and it would really raise a red flag if the door was closed.

I personally don't think it is a good idea for your 15 year old sister to be living with you not her mother... but that's my opinion.

I would have a calm discussion with my boyfriend, no judgement or accusations. I would just tell him HOW I feel when he does certain things (like ignore you, and compliment her on her clothes, etc).

Be honest, don't get emotional.

And have the conversation when your sister is not around, maybe while you guys are out for a walk or sitting around at the park... somewhere neutral.

She has a crush on him, so this attention can give her the wrong idea. And at 15 her hormones are ragging and it is hard to say where it can go. If he is not treating her like a little sister this can go down hill real fast