be a thorn in (one's) side(redirected from been a thorn in their side)
be a thorn in (one's) side
To be constant or persistent cause of annoyance, frustration, or trouble for one. My professor was an environmental activist when he was younger. Apparently, he was quite a thorn in the oil companies' sides at the time. My little brother is such a thorn in my side—he always wants to do stuff with me, especially when I'm trying to hang out with my friends. This project has turned into a real thorn in our side.
Farlex Dictionary of Idioms. © 2022 Farlex, Inc, all rights reserved.
be a thorn in your ˈflesh/ˈsidebe a person or thing that repeatedly annoys you or stops you doing something: This patient is a real thorn in my side. He’s always complaining of feeling sick and I can never find anything wrong with him.
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