Petty good man, the chapter is good, but there are a few words that need to be added or taken out.

There needs to be a to between trying and hide.

Big Mac couldn't say he was partial to stallions. Not in the slightest. In fact he had even taken a liking to a cute unicorn mare that he regularly ran deliveries to in a small remote village. This seemed to strike a strange contrast between his usual preferences and the massive artificial cock currently lodged in his backside. It had been a particularly painful experience for him when he had gone to buy it, the poor guy, already a stallion of few words, might as well have been completely mute trying hide his embarrassment while the salesmare idly rang up his purchase.

Needs to be an on after dragged.

In the time after the accident Big Mac hadn't been able to get the memory of that feeling out of his head. As the days dragged this obsession had spurred him to do anything he could to chase that high. At first he had simply tried clopping, but no matter how carefully or vigorously he stroked his member, or how long he edged himself in desperate attempts to come close, nothing even remotely compared to that one event. Further attempts had led him to explore his neglected rear. That area had always been an unspoken taboo for the prudish farmpony. It was for one thing, and one thing only. Anything else would be unthinkable and dirty.

Wouldn't needs to be taken out.

Big Mac was aware Scootaloo was older, and sexual topics were a thing that wouldn't be beyond her at this point. That said, she was still a filly. It just didn't wouldn't feel right explaining to her that she had stimulated him in such a way.

But the rest looked pretty good