We might as well get a Paranorman moment with an off-screen love interest. Lefou was literally a walking gag in the original and I doubt his role is gonna be important enough for his sexuality to be the source of such controversy. So there's really nothing indicating ANYBODY that could be the source of his affection.

It'd be kind of weird if it was Gaston honestly, especially if he turned out to reviprlcate, since that would basically be saying "all those aggressively hyper-masculine narcissists are actually just in the closet! Closet homosexuals are the real villain!"

Kind of undermines the original's message regarding masculinity and gender roles in general