Some time to work in class. (Poop)

Ms. Cole wraps up her planned lesson, and assigns some practice problems. "We've got about 20 minutes left in class. So let's use this time to work on anything you need, and I can go around and help anyone who isn't sure they understand the material. Anyone need help now?"

"I have some questions about the approach, Ms. Cole!" The blonde girl to your right calls. "Be right there," Ms. Cole answers. Your desk had been scooted a little to one side when you came in so while Ms. Cole is leaning over helping your classmate she ends up shoving her ass right next to your desk, giving you the best view you've had all morning, as occasionally a drop of piss beads up and drops onto the edge of your desk. You pretend to look like you are working while you stare admiring your teacher's lower region on display.

After a few minutes, you see her asshole start to wink a bit, and you nervously edge your books off the desk and into your bag. Sure enough you see Ms. Cole's asshole starts holding open a little more, and a dark brown lump sitting just inside her entrance. She continues subconsciously flexing her anus to try to push it out, but the turd refuses to give until eventually you hear her grunt and she turns her head to look at you. "Ugh. I always have trouble going in this position. Mr. Benning, would you be a dear and hold my asscheeks open for me?"

"S-Sure thing Ms. Cole." You reach up and pull your smoking hot teacher's soft ass cheeks apart, and the tip of her brown log slips out of her butt a little bit, where it jams up again.

"Hey man, don't be ginger about it, you're probably going to have to stand up to get a good angle to spread her wide enough." The sleepy-looking dude to your left suggest.

"Right." You stand up and walk around to the side of the desk Ms. Cole is on so you can lean over her back and really pull her cheeks open. You aren't paying attention to the fact that this puts your rock hard cock up against her arm while she's helping the blonde girl.

When you spread her cheeks this time, the massive brown buildup in your teacher's ass gives way and a python of shit shoots out across your desk. Her poop is so long that it wraps up in a loop on your desk before it comes to a stop. "There you go, Ms. Cole, all done." you say. "Thank you, Mark, I feel much better, you are a gentleman, a scholar, and a plow horse in the sack." Ms. Cole answers politely without looking up.

The blonde she's helping, however turns to give you a smile when she notices your massive hard-on. "Omg, did you get that from helping Ms. Cole out? I think it's so sweet that you find such beauty in the day-to-day mundane." She coos.

Ms. Cole, turns to look at the issue, "Oh my, how rude of me. The plow horse comment was just meant as that common turn of phrase, but if you need to use me - she wiggles her rear end - to take care of that erection, Mr. Bennett, then by all means help yourself." She then returns to helping the blonde girl with her assignment.

(Author's Note: While there are toilets that can be used for pooping, there is no strong obligation to do so. Some people prefer to use them if they can, especially if they are ill, tend to be angry and vocal shitters, or expect their dump to be particularly gassy, wet, or take a while. Additionally in places where a certain degree of silence is expected like a library, funeral, or during a test excusing oneself to void bowels is considered more polite - much like stepping out to talk on the phone or blow one's nose.

On the other end of this people in positions of responsibility are more expected to just go ahead and go wherever they are. No need to derail class, halt a surgery, or cancel a meeting when you're the person in charge.)