I don't think the game intend to "immerse" you with the world. Not with the amount of meta information currently given to you.
The only suggestion I can give is: Say no.
Wyll and Gale will approach you if you are goody two shoes, but once they rejected, they will not approach you.
They're adults, they can handle the "no" - and you can still progress with their quest.
I was going to say this same thing. Maybe it's because I'm a woman, but I'm terribly used to unwanted people insisting on flirting with me, and I just say no. In fact, some insist even when you tell them no, so in reality I see it as quite realistic and it doesn't spoil my immersion XD
