We now know that the MC's recollection of the confession to Erynn is either incorrect or missing information.
We need to see her memory of it, but I suspect he was never rejected, and she just deflected the questions as other people were there.
er "Don't ever leave me again.. Okay?"
er "Besides.. I still owe you an answer.. Do you remember..?"
Erynn told Alexis how she feels about the MC, but they were never together.
Alexis was a shitty friend with how she has acted, but Erynn is acting as though she slept with her boyfriend. I can understand not going after someone your best friend is interested in, but it is not as if Erynn was actually doing anything about it.
Erynn then accuses Alexis of doing something similar with Ethan (if she really believed that, why did she stay friends with Alexis)