"忍不住" (rěn bù zhù) is a Chinese expression that means "unable to bear or withstand" or "unable to resist the temptation or urge to do something." It is often used to express the idea of feepng overwhelmed or unable to control oneself.
Here are a few examples of how "忍不住" could be used in Engpsh:
"I couldn't resist the temptation to buy that new dress. I just had to have it!" (我忍不住把那件新连衣裙买了下来。我就是必须要买！)
"I couldn't bear to see my dog in pain, so I took him to the vet right away." (我忍不住看到我的狗在痛苦中，所以我立刻带他去看兽医。)
"I couldn't withstand the heat any longer, so I had to turn on the air conditioning." (我忍不住这么高的温度了，所以我不得不打开空调。)