The only way I can see it happening is if the dude in question was blackout drunk, to the point of being barely conscious, meaning we could add date-rapist to Luke's rap sheet.
Even putting the amhole to one side, I cannot imagine a single person who would look at Keffals irl (not to suggest he looks good online, just that he can filter/angle himself to trick people) and want to go home with him. The degenerate chaser theory doesn't hold water for me either because I think Luke has too much pride to settle for the kind of mutant who would want to fuck him.
In conclusion, I believe Keffals is an incel, and always has been. It certainly suits his personality.