Okay, so here’s the deal. Changelings are horny little buggers.

They feed on love. Doesn’t matter what kind. Could be romantic, could be familial, could be the short-burning passion of a honeymoon couple or the calm, comfortable love of the elderly. They can feed on baser emotions too, if need be, which includes lust, but this is like trying to live on nothing but fast food. It isn’t good for you.

All that being said sex is a very, very effective tool in a changeling’s arsenal. Sure, it’s not the best way to feed and it’s not required for every type of love they can make a meal of, but oh boy if it doesn’t keep the spark alive when you’re pretending to be someone’s lover! Whether they evolved or were created changelings have been blessed with extraordinary libidos to keep their victims satisfied and placated, and incredible stamina to make them at least appear to be generous lovers.

Regrettably this effect is not limited to their disguises. A changeling back in their home hive is just as horny as on excursions, only now there are no ponies that they can regularly fuck silly. And most monarchs, especially those pushing the old Royal line about suppressing individuality, expressly forbid fraternisation of that sort between drones.

Some hives, therefore, make use of captured ponies to keep their drones sated. They can’t take one pony for each drone in their number, else Equestria would be literally emptied out to slake the changelings’ collective lust, but a single pony can service many changelings, when properly motivated, and so they are relegated to use as public relief items.

Here we see one such lucky soul, fresh from what one can assume to be a good facefucking, with his next ‘suitor’ already eyeing him up. The collar and underwear are really just window dressing to keep the drones happy, but they also do a good job of keeping him pent up. Enough good fucks without a change to properly cum, and enough much-needed releases every so often, and he’ll end up being so malleable his captors can probably turn him into a far more willing and proactive servant. Who knows, he might even be allowed out of those restraints!