으세

The 세 inside polite 세요 requests

In every line here this appears inside a polite 세요 request, or a playful respelling of one, attached to a stem ending in a consonant: have a go yourself sometime, take a seat, take what he says with a pinch of salt. The 세 part carries respect toward the listener while the 요 carries the politeness, so dropping the 요 changes the tone completely. Three lines end it 세호, 세용 or 세셈, which is an online habit that makes the request sound cute without changing what it asks for.

Register: polite everyday requests