Wiggle your fingers

You decide to be funny and wiggle some fingers through the hole back at her, knowing she isn't going to be sticking her non-existent cock through the hole. However you kind of wish you could just stick your dick through there as you are super horny at the moment.

"Are you sure you want to suck my dick? I always pictured you as a pussy sort of person." She says, as you hear her stand up.

"I'm totally into pussy, but if you have a dick, I'll suck it right now. In fact for helping me out with the pants, I'll let you fuck me in the ass." You joke as you start putting on the sweat pants. As soon as you finish saying that you see a bright red cock head start coming through the hole. It barely fits through the hole it is so large. It keeps coming and you have to back away from it, falling and sitting on the toilet. Once it's all the way through it's a massive 9 inches on your side of the stall, thicker than a paper towel cardboard tube, it glistens with pre-cum down it's entire length.

"Well, you going to suck it or are you just being a huge tease? You did say you would." She says through the wall. You had said it, and you don't go back on your word. You lean forward and start licking the tip, it tastes a little salty but pretty good. "That's licking, you should be sucking." You acknowledge the point by taking the head in your mouth and swirling your tongue around her urethra. You start to suck her cock as best you know how, trying to avoid your teeth and giving her as much friction and movement as possible. You keep this up for what feels like 20 minutes and your jaw is getting sore, when she suddenly says "I'm going to cum, just swallow all of it or you're going to ruin the rest of your clothes." You think she's probably right and try your best when she starts unloading in your mouth. You can barely get it down as fast as it's coming, but you manage and finally she finishes. "That was amazing, we should do that every day." She says as she withdraws her cock through the hole. You can see her cock and balls through the hole as she starts putting her pants back on.