See, this is it in a nutshell. The OP is saying the exact circumstances are implausible. What she’s not saying…
Not that men turn down sex. That’s totally plausible.
Not that men find certain women too unattractive / unappealing (age or weight or looks) to have sex with. That’s totally plausible.
Not that men will be brutally honest about why they rejected some woman’s interest. That’s totally plausible.
Not that some men will even frolic in a sensual manner with some women and yet not have sex with them. That’s plausible enough.
Not that men won’t go away with a woman on a trip (or have a special occasion dinner, whatever) and not do any breaking up until after it’s over to avoid any awkwardness. That’s totally plausible too.
What the OP is pitting is that a man won’t specifically go out with a woman (1) that he already knows he probably won’t be attracted to, (2) date her for several months anyway, (3) without having already gotten intimate with her, then (4) go an extended getaway with her where all they do is stay in bed nude, yet (5) still don’t have sex, where (6) at no point during all this, she doesn’t ask why they are not having sex. Then comes the inquiry and (7) he’s brutally honest when he hadn’t been before, but still reiterates a sentiment that (8) just happens to dovetail with her view of herself (She’s an awesome catch, except for that pesky age thing!) and her livelihood.
Now, for the last billionth time, I can see parts of that scenario happening simultaneously. I cannot see them happening all together at once. For example, in Shag’s case, I can’t imagine he’d invest that much time to begin with. In my own, if I’d been rebuffed like that, I wouldn’t let the rejection go on all damn weekend. I’d have to know sometime after attempts, I dunno, three and twelve. I don’t think most people could stand the repeated rejection that long and just keep going back for more.
So, if everyone that keeps all swearing this is soooo totally doable, do you really, honestly believe that every, single aspect of this (as written) could add up to most men doing exactly as this man was alleged to do? Not just bits, but EXACTLY.