Delta really had to go and in desperation forgot to lock the outhouse door so because of it, ponies outside the outhouse thought it was vacant when it should've said "Occupied". While Delta was the middle of relieving herself, somepony who also had to use the outhouse thought it was vacant and opened the door but only to find somepony else in there. Both ponies stare at each other for a second and the one who opened the door quickly closes it. Delta is really embarrassed and stops going for a second to lock the door. She carries on to relieve herself and thanks to fixing her mistake nopony else walks in on her.

Don't you guys just hate it when someone walks in on you, I do, it feels so embarrassing. That there is why you should always lock your door or even knock. At home is one thing but in public is another. Even though ponies and creatures don't wear clothes, they still want their privacy when they relieve themselves so being walked in on is just as embarrassing as it is for us humans, even if they don't use a bathroom half the time, some are more civilized than others. As we can see here, Delta is very civilized while some of her other friends are not.