How does your muse flirt? - for Artak?
Artak can be a flirtateous little shit when he wants to be. He's generally not shy at all, so he tends to be very straightforward with it, although he does at times enjoy to play the back-and-forth game just for a little fun. They've kind of adapted to human customs after years on the surface, so if they were to try to romance a troll, it might get a little bit more tricky as it's not what they're used to, but that only adds to the challenge. Humans, on the other hand, he mostly just considers fun to play with on occasion.
Now, if all they're looking for is a good romp and they don't want to bother with all the complex games leading up to it, they might just find someone reasonably attractive, buy them a drink and ask point blank if they'd like to hook up, without wasting any efforts. On the rare occasion that they're actually interested in someone deeper than that, that lucky(?) person is getting a show. Suddenly he's wearing crop tops and tight pants, showing off what he's got, probably bending down to pick something up at just the right angle. Artak isn't very romantic, that is to say, not at all. With him it's all about physical attraction (and possibly alcohol), although they do at least know the good old basics of holding open doors... to a degree. Well, they'll try to do it if it's important to their object of affection, but it does not come naturally, and it's rare for someone to be deemed important enough.
Thankfully actual feelings never actually surface for them, because they'd be absolutely terrible at handling those. "Just sex" is easy to get, but a date? A pretty strong sign that Artak actually likes you and doesn't just want to get in your pants is when he behaves like a dick to you for no apparent reason. Good luck.