Maybe im just reading to much into things. After this update I dont feel like there is any need for them to admit their feeling anymore with how often they are kissing, how bold Erynn is getting with the MC. To me it feels like they kind of already have with their actions. But I do agree I would like the MC to go to Erynn or someone for some comfort as I wouldn't want the conclusion to the reveal to be done and over with within 5 minutes.
I believe he's talking about the path where you are dating Alexis but kinda has Erynn waiting in the wings, wishing for something more... It's totally different from the slowly progressing relationship with Erynn(without Alexis).
Thus far the Alexis path has been a no exit adventure, no matter how hard you try to piss her off we don't get to "escape", it's like a blood oath... unlike most other girls who constantly have exit opportunities... maybe this will be it.
From a meta perspective there's no reason to freak out about Santiago being Alexis father, i'm sure it will be explained soon what exactly their relationship is... in universe i kinda expect a freak out from the MC... since he doesn't know "incest isn't allowed" and he's in the clear.
I can see him running from the bar leaving Alexis confused and telling her "we can't see each other anymore" the next time she tries to talks to him... without any explanation(something similar may happen in the Layla path) because of what he just "learned".