I think he would be Mark's stalker (he is mentioned in Mark's route and in the Mark episode).
I already did Gil's route and he didn't show up, and I mentioned Mark's stalker because maybe there's just one stalker in Mark, Lars, and Parker's route.
I think so. I have quite a few theories.
(I already did Gil's route and he didn't show up) I did it with the guide, here it is in case you want it (it's not mine and I don't know who created it, I think the creator of the game) : https://docs.google.com/spreadsheets/d/1opecc1Wkh4iUxIYTlF0c5NtbbmmQ_30fIH2b5JXb...