1 definition by Momo:)
A combination of the two words "Upset" and "Obsessed" used to express negative emotion caused by heavy affection/ obsession for someone or something.
A: I'm totally down because X. ghosted me again, I just want them to care about me, the way I care about them.
B: Seems like you're totally upsest with them
A: Fuck you
B: Seems like you're totally upsest with them
A: Fuck you
by Momo:) February 16, 2022