>>101597333Not only is there a time skip but we don’t actually see a lot of Zuko and Mais history
It’s clear through a flashback that Azula always wanted to push them together as a favor to Mai, and now that Zuko isn’t banished, it finally happened
Seeing as how their relationship wasn’t the focus of the series, it’s not actually a big deal if they don’t show build up
Actual relationships can happen very quickly, so it’s not a matter of realism. And obviously we do see the ins of their relationship during the beach episode