on thorns

continuously uneasy, especially in fear of being detected

焦虑不安，如坐针毡（尤指担心被察觉）

there is no rose without a thorn

(proverb)every apparently desirable situation has its share of trouble or difficulty

(谚)没有无刺的玫瑰；世上没有十全十美的事；有乐必有苦

a thorn in someone's side (或 flesh)

a source of continual annoyance or trouble

经常使人苦恼（或生气）的事（或人）

the pastor has long been a thorn in the side of the regime.

这个牧师长期以来一直是令这个政权头疼的人物。