44 flopped set, limped pot

you raise super big i guess

Yes, raise big time here.

Raise flop big sounds good to me

Isolating the fish preflop with 44 is completely fine imo, but overlimping is probably also fine. As played, we should raise the flop, ofcourse. Probably something like 10 BB would be fine.

We should raise more here to charge for draws and let them pay for weaker hands.

You can also fold. That will fool him totally. He'd never expect you to fold such a good hand:f_biggrin:

But raising starting now is the best option. You have to do the math (away from the table) yourself, but hope he has KQ exactly and calculate sizes so that all bets have a reasonable chance of getting called and the river bet should be all in (without being HUGE in proportion to the pot). If he doesn't have KQ and folds, well, you'd not get much value anyway by slowplaying. There are draws to consider as well on this board.

EDIT: I now see this is 4-ways. (Sort of forgot about the blinds.) Absolutely raise.