As a writer myself, I actually disagree. There's plenty of plot development opportunities if he does decline. It'll be a massive blow to Alex's ego, not to mention the whole "can't get it up" issue is still a thing, and he'll probably end up wanting him more BECAUSE he rejected him. A big part of keeping a plot interesting is denying the reader what they want so they keep reading, which makes the pay off that much better. Logically, if he agrees and they have sex, that has it's own plot benefits, but if he declines now and later concedes, the writer will have the aftermath of the rejection to write about AND the benefits of them eventually doing it after Alex manages to convince him. If it were me, I'd have him remember his dignity and walk away. Although, I do agree that the writer is probably gonna have him agree to it just to save time as I doubt they intend for this series to be very long.
I would prefer for him to walk away and drive Alex to really take a look at his life and truly fall in love
We all know you're going to drink it otherwise that's the end of the story...
On the other hand, I understand your feelings I wouldn't want my first time or anytime for that matter to be treated like nothing...I wouldn't want to be "fap fodder" for someone who could care less