expression
overstay one's welcome; be a guest too long
Idiomatic expression literally meaning 'one's buttocks are long', used when someone stays too long as a guest, especially in a neighbor's house or similar informal visit.
隣の奥さんはいつも尻が長くて、なかなか帰らない。
The neighbor's wife always overstays her welcome and never seems to leave.
ちょっとお茶に呼んだだけなのに、尻
I just invited them for tea, but they stayed way too long and it was a problem.