Even trying to buck was impossible, considering how much heavier than him Sephiroth was. Mello grunted quietly, trying to squirm, but gave up out of necessity.

"Why are you doing this?" he demanded in a low growl because focusing on anger was a lot easier than thinking of exactly what was happening here, what Sephiroth wanted him to do. "All it's serving is your sick fetishes. I'd be just as unlikely to escape a locked room with a toilet," he pointed out. "The lowest criminals are treated with more decency!"

Dogs, even! Not that Sephiroth cared, he was sure. But he was getting desperate and trying to ignore it and it wasn't working out easily.