Looking up exs

So I’ve just found out my partner has been looking his ex’s up on Instagram. We have a daughter together and I’m currently pregnant with our second baby. Things have been a bit weird we barely touch each other anymore etc. He’s been really mean with some things he’s said recently and is always saying I’m lazy and how I don’t love him anymore or find him attractive which is definitely not true I just don’t know when he’s gonna snap so I’ve avoided getting into situations that could make him react that way. I don’t know what to do or whether to say anything to him as then he’ll know I’ve been creeping. Any help would be reaaally appreciated