Maybe this will be an opportunity for them to talk to Abe? Someone who's been in a similar position, and could offer some insight into having a relationship with a classmate and could maybe provide some perspective for a couple that's super into each other, yet terrified of going public?
I don't think they've every really said just why they're so insistent on keeping their relationship a secret. The closest is that flashback featured here, where a girl-girl couple is met with teasing. (given the personalities we've seen so far, I can't belief that it would be actual bullying rather than some good-natured ribbing) There's obviously a lot of reasons to keep a queer relationship hidden, especially at that age, in real life, but this has never struck me as the type of manga to pull a "And then Chidori was kicked out onto the street because her family are homophobes" plotline, so I'm still sorta uncertain what they're so afraid of.