an expression used to accuse someone of having an affair or to behave secretively [colloquial]
Definitions (粵典–words.hk)
語句
歇後語:有條路 a dog goes up the roof→有條路 [yáuh tìuh louh] there is a way ■used to accuse someone of behaving secretively, especially of having an extramarital affair.
Examples (粵典–words.hk)
Cantonese
狗上瓦坑
狗上瓦坑
to accuse someone of his secret behavior or channel; literally: a dog goes up the roof