RPGMemes

I want to point out that the player would need to identify it as a glory hole and not just a peephole or something. They would also need to think it's a normal thing to find in the world and not something out of place. They would also need to be comfortable enough with the other players to engage in sexual roleplay with a wall. And in this case, you have clearly created a very perverse game world for your players.

The alternative is you just deciding to tell your players "you see a hole in a wall that you think could be a glory hole. ...Anything you wanna do about that?" to which most players would either ignore it or check the hole for traps before ignoring it.

In short, I don't think the problem is the BARD being horny here.