You run into Purple Diamond at a hot spring you thought was empty, he can't help but find you adorable so he kidnaps you and claims you as his pet.

(Request) - They asked for a male diamond keeping you as a pet, so I made an alternative universe from Steven Universe. Where, as the request puts, makes them all male so this is MxM.

Art made by Dall-E 3 - the prompt I used, (Illustration demon, male royal, made of purple diamond, unique face, purple diamond in chest, inside a rich castle made of diamonds relaxing, royal clothing, humanoid.)