Okay, this ship is freaking OTP! I love this ship. Hiccup and Astrid are both very emotionally healthy, and this relationship is also very healthy. Like, yeah at first Astrid didn't really like Hiccup, but it is highly likely she had feelings for Hiccup before the romantic flight, as shown in the first movie (and according to the fandom and shipping wikis). It's absolutely beautiful watching their dynamics, and it's highly likely that they will get married in HTTYD 3. I will not be happy if they don't get married.

Edit: *happy tears*