It was on the very first XMFC kink meme I ever saw. They were all in a room, maybe a hotel? Charles is the only omega. I remember I part has him in the bath pleasuring himself because of his heat, and making loud noises. The others were in the other room listening. When he finally came out of the bathroom, they all took turns with him. Erik was the last I think.

I don't know if it was a wip or if it was complete. Please someone find it for me, I've been looking for it for a long time.