"Hey!" You shout. "We had a deal... I let you now you gatta fed me!" Suddenly you hear that sly smug voice in your mind.
"I hadn't forgotten our deal." It purrs as you feel a pain in your groin.
"Owwww what the fuc..." You grunt as you watch your own stiff organ tense and flex almost like it's orgasming. Then as you stare in stunned horror your organ begins to bloat and blacken. Slowly growing longer and thicker, your helmet flattening out. Into that familiar mushroom shaped equine flare. "Oh my god!" You moan as the big black organ grows and grows until it's tip is pressing against your chin.
"You may now satisife your hunger." The amused voice gloats, as your hot mouth ungulfs the big blunt cock head...