[Roland]

What to do on 3rd depends on the player. If he plays every hand in that spot I would raise on 3rd.
Since you didn’t, 4th street is a bit tricky - would he bet there with anything? If yes, you should probably raise; if he is the type to slow play big pairs though, I’d fold. The pot is just to small to fight for imo.
Oh, and check the river. Whatever he raised you with on 6th, he’s betting it on the river, so the $$$ will go in anyway. If you bet yourself you risk a raise though.