Not quite sure what his looks have to do with it, a client is a client. He might genuinely like you, or he might just be looking for free sex. Who knows.
You say you have a good connection with him. What does that mean? Usually, when we fancy someone, our feelings make us certain it's a 'connection' when it is often just lust. You say the lines have been blurred. Yes, they have, because he did not pay you for your time.
As an escort, you know that money ensures everyone knows where the lines are. However, the line has well and truly been crossed. 'Don't shit where you eat' as the saying goes.
If he wanted to see you again, yes, he could book. But, given you've already had sex with him for free, what is to say he is not going to manipulate the fact you have feelings for him into giving him a freebie? This is telling:
he messaged me really nice things but also always with a sexual tone
Personally I would just block him and not give this any further thought; it is the best thing to do.
This is just my opinion though, others might feel differently.