Martin Hannibal

Here's what I think, although I'm probably incorrect here, but here goes:-

If it's four handed and being in the cut-off, the opening raising range for a fish or a good player is quite wide, although I wouldn't discount him having a hand some of the time.

Just as you may not give him much credit him for his raise, he may know you are thinking this way sensing weakness in your raise. I think a re-raise from the SB would carry more clout. However, overall I think that a flat call out of position on his part would leave me to think the player may have a suited ace or pocket pair?

On the flop he checks as you expect and I definitely like the continuation bet from you. His check raise, raises some more questions. Would he play this fast with a set or straight? or would he donk bet out? Could he have a decent or nut flush and having a semi bluff? either way it seems he doesn't want another card to come off!

Overall, I'd say there's no way to be sure. Maybe min re-raise and see what happens? But folding might be the best play?

Yeah I probably would have continuation bet the flop. 1/2 - 3/4 -full pot? Give him the wrong odds to call on a draw? Plus, you have the lead in the hand. If he calls I probably would've donked off some more chips on the turn with a second barrell or check re-raise before I realise I'm beat haha :D