Yes, a make-shift glory hole

While you´re still thinking about a way to escape the cashiers eyes, you hear something falling to the ground in marlas cabin and then Marlas voice from behind the curtain. "Ey, check this out.", she says, quietly, "Go in the next cabin to the left."
Confused, you do as she says, making sure to wait until the cashier looks a different direction as not to arouse any more suspicion.
Inside the cabin, you closs the curtin, and look around, confused. There was nothing here, except for a big mirror and a small wooden board to lay your phone and wallet on while dressing.

"You hear me?" You hear Marla ask, inches away, behind the thin wood wall.
"Yes. But what exactly should I do here?"
"I managed to remove this wooden thing on the wall, maybe you can do the same. I dont think the wall continues behind it."
Understanding what shes getting it you quickly examine the board, then you grab it and slowly begin to move it side to side, loosening the nails holding it in place.
"We´ll get in a lot of trouble if we´re caught" you say, knowing neither of you is going to stop because of that."
"Yeah", Marla answers, "But I´ve seen your dick pushing against your pants and it looks pretty uncomfortable. I´d be a bad friend if I didnt help you out."

Then you manage to sepperate the board from the wall and carefully lay it aside. There was now a hole just were it hung, Marla was right.
"I think you know what to do." Marla says, and you hear some shifting on the other side as she supposedly got down on her knees.

You do, and shortly after, you carefully direct your hard dick through the whole sapperating you two.