Is he over his ex? Or am I a rebound?

idk

There’s this guy I’m trying to get to know as a friend before we date. He’s been single for three moths. We went out for the first time yesterday. He opened up about himself pretty quickly including about his ex. He kept saying he hates her but while he was talking about her he mentioned he saw her a couple weeks ago because she wanted to talk. If he hates her so much why does he still talk to her? Also he still follows her and he even liked a bikini pic she posted 2 days ago. Should I give him a chance and hope he will get over her eventually? I know it’s only been three months so I don’t expect him to be over her immediately. I’m just hoping I’m not a rebound. I don’t want to date right now anyways as I said just be friends. Is it worth trying?