Astarion will proposition you if he likes you enough. Gale used to do that too, but he gets bugged in a different way with every patch so it might not be the case these days.
The first time I got Wyll's dancing scene was the first time I played Durge. Gale wasn't with us and couldn't insert himself into the second romance slot anymore, so poor Wyll who was mostly staying in camp got it. Funny how this game works.
