He puts on a mask to scare her off!

It sounds like you're describing a common scenario in short videos or #shorts where someone puts on a mask or costume to surprise or scare someone else for entertainment. These types of videos are often created for humorous or playful purposes and can be found on various social media platforms. It's essential to ensure that pranks or scares are carried out safely and with the consent of all parties involved to avoid any negative consequences. Enjoy the fun, but always prioritize the well-being and comfort of those participating in such activities.