There are plenty of straight relationships in the story, so why not? Gay people exist just like straight people do, and romance has always been an important element of storytelling.
That was kind of ambiguous in regards to it being a friendship or him wanting more, but even without Taelia I believe it was established during the Tiragarde Sound questline that he had a romantic history with one or two of the female NPCs we encounter. He also falls for the harpies’ charm effect in a rather hilarious part of the questline, but I don’t think it’s been established if their magic depends on them matching a victim’s preferences or not so that may not even matter. All any of this would mean though is that he’s simply bi rather than gay.