For me I'd say the answer is both yes and no. I've absolutely noticed that when I started wamming with my wife her simply dipping her fingers in some chocolate sauce was enough to take me over the edge. Then it had to be chocolate on her body, then messy clothes, then other foods, mud, paint and so on. For a while I worried that my messy interests were running their course and I'd soon lose interest altogether. That doesn't seem to have happened, though, over the ten years or so we've been doing such things together and I think the person who mentioned the idea that humans will always seek out novelty has it right. My imagination seems to keep on coming up with new things that excite me, but they're always some form of WAM. It's been great fun, and I think it will go on being so. And while a degree of novelty is part of the fun that doesn't seem to mean I lose interest in WAM any more than in sex itself.