How can you tell if someone likes you?

So I’ve been talking to this guy for a while and I’m starting to really like him. But he is so hard to read!!!!! He’s really mysterious and it’s hard to tell how he’s feeling. When ever I hang out with him I feel a really good vibe, but when I’m not physically with him he acts really distant. Something tells me he likes me, but I really don’t know and I’m nervous to ask him because I don’t wanna seem pushy but:

•I met his mom

•he pays for everything

•he acts extremely affectionate in public (hand holding, kissing, hugging, etc)

But he acts so distant when we’re not physically together, I don’t really get it.