Yeah there's no reason really why Hook can't carrying on flirting wildly and inappropriately with other women while being in love with Emma. It doesn't mean he's interested. It's more of an act, a strategy to annoy the other person or put them off balance or get something from them, and apart from certain exceptions he would probably run a mile if they did respond to it. It would be fun to watch Emma roll her eyes while he was doing it or have her snarking about it.
It isn't too bad at the moment but unless Emma starts giving some more encouragement or he walks away or moves on, I could see it all going a bit friends with detriments https://xkcd.com/513/