Maybe golden freddy's sex scene (enter 6969 for custom difficulty).
Viewing post in 🔞Five Nights at FuzzBoob's: Definitive Edition comments
She does that on rare occasions, and she just pops up on your desk. If you want to stop her from jumpscaring you, go to cam 3 on your monitor, and click on the poster on the wall, and she should disappear. Don't panic when you see her, because she takes quite a while to jumpscare you, she'll sit on your desk, stand up, and then jumpscare you, so you have time.