I have a couple of fantasies.
I'd love to give cleansing enemas to a man until clear, then fill him again with one or two quarts, however much he can comfortably hold. Have him lie back, then insert my vibrating, inflatable butt plug inside him, inflate it so it's nice and snug and fills his bottom well. Then I'd get into reverse cowgirl position, turn on the vibrations and ride his cock while he holds the water. I'd lean forward towards his toes, grab onto his calves and push back against him to fuck him hard. In this position, not only would he have a great view, but he could use his fingers or a toy to play stimulate my bottom. Only after he's brought me to orgasm several times would I let him get up to expel. Depending on my mood and his level of submission, I might make him expel in front of me.
My other fantasy is to be given cleansing enemas until clear. Then slowly given a warm oil enema and letting it heat up to my body temperature. When it is comfortably inside me, I want a man to enter my body and fuck me while I'm holding the oil. It would have to be an amazing ride for him, so wet, so tight, so slippery, so hot. He could use a vibe on my pussy and bring me to orgasm, making my tight bottom squeeze even tighter around his cock. I'd love to feel him cum inside my ass. I've always loved the way that feels.
I have a couple of other fantasies, but they're not enema related. I'd love to be fisted and I'd love to be penetrated by two men at once. One in my pussy and one in my bottom. And if there happens to be a third gentleman for my mouth, even better.