Dating

Is my boyfriend being suspicious?

Okay so there’s multiple times where this stuff has happened with my boyfriend so I’m going to talk about this time that just blew the straw for me. His younger sister (14) has been in town. Mind you my boyfriend is (18). He’s always told me how much he prefers his youngest sister over his other one (16). Which I never understood why because the 14 screams slurs and posts half naked photos. Anyway, since she’s been staying here for a month he’s been flakey. He always responds fast, we’ve been dating for a year and he has a shitty sleep schedule and he’s not a busy guy so he usually responds like asap. On the other hand, his sister just posts sex quotes and pics on snap all day like ALL DAY. I notice everytime he doesn’t respond for hours or even answer his phone, she’s not posting. Which is abnormal. I’ve noticed this pattern and a lot of other things. Today blew the straw for me because I texted him 5 hours ago and he just randomly stopped replying and she stopped posting again. I finally called him and it took him till the last second to answer and his camera was at the edge of his bed and he had his glasses on. I asked what he was doing (HE WAS TOO ALERT TO HAVE BEEN JUST WOKE UP). He said “I just woke up”. I brought up how he’s wearing glasses though and he said “oh I meant I was laying down waiting for you to respond.” But I responded four hours ago? Three times too? Anyway I just saw all the signs on FaceTime I had to hang up and legit put my phone down. Am I crazy or?
Is my boyfriend being suspicious?
Post Opinion