i wonder what they’ve been up to
Tumblr sent me to your post about the noncanon couple that is Zatara. Zuko did the do with Mai, not Katara. Katara did the do with Aang, 3 times at least, unless if you're willing to write off 2/3rds of what happened in the Legend of Korra. Makorra is also extremely unhealthy as Mako is not only unfaithful, but he's also abusive (à la Book II and part of III). In short, all of what you like is problematic at best.