Boyfriend calling another girl beautiful.

Just saw it in his messages on Instagram. he replied to a girls story saying "You're Beautiful❤". we've been together for 4 1/2 years and are fine, he's out of state hanging out with a guy friend though. I'm a little hurt mostly because he never or barely calls me beautiful ever. :( thoughts? EDIT: I'm so upset guys. I haven't even been able to sleep much. and my stomach hurts. I've dealt with this with him quite a few times, just him making me look stupid on a lot of occasions, and I feel like he should know better especially since like 2 years ago I broke up with him over this. not being able to trust him. and he knows it's a battle me trying to gain his trust ever since. so why the fuck keep doing shit like this :( he's probably just with me for the hell of it since its been a while together. ugh