I made a puzzle without a solution and now my players want me to solve it for them
Okay, so I made a stupid mistake. I made a puzzle for my players and told them they needed "the shape, the voice, and the memory of the sea" for a ritual, thinking they would figure something out. It was literally meant to be whatever they came up with.
Fast-forward to the end of the session: I asked them what they thought about the riddle and what they wanted to do next session, and they want to ask an NPC for the solution to the "shape of the sea" part. I told them above table that I'd rather they figure out the riddle instead of simply getting the answer from someone else, but I'm pretty sure one of them is still gonna ask an NPC for the solution, especially because they think it's gonna be something really smart and witty.
Can anyone help me figure this out?