you went to the flop 3 handed, if anyone has 4c5c you are capping every street with them unless they are an absolute fish. you risk losing up to 3BB by slowplaying the flop.

also, you want to raise here a lot more against looser players as they are much more likely to pay you off. a tight player may find the fold button later on whereas a loose player will most likely call down to the river with KQo. (I know i would)