Wow. You are so right. I never had this option, since I never hired Sorn, but the very fact that this line exists is extremely off-putting.
Larian, what are you doing? It's just plain disgusting. If it was supposed to be a joke... well, whoever were the clowns that added this line, maybe they considered it funny. However, most of BG players are not idiots, they deserve more elaborate humor. Not about how any of your companions is "boring" in that way. And why only Gale is a target for this "brilliant" humor? It sucks.
If they intended it to be serious, that sucks even more. Then I sincerely don't understand what was the point of it all. They created such a character, made him so attractive, wrote all the amazing romance lines, gave him the hottest scene in a game (which took quite a lot of budget, for sure) and then... This. Congrats Larian, you created something people love, and now you ruin it. Very respectful of your fans. Such lines should have been removed long ago.