To drop someone/something like a hot potato means to disassociate oneself with someone or something instantly.
To discontinue; to get rid of very quickly.
To quickly stop being involved with someone/something.
1. I dropped the idea like a hot potato because my boss looked disappointed when I started discussing it.
2. He dropped me like a hot potato when he found out I had been married before.
3. My best friend started dating this man but when she learned that he was broke she dropped him like a hot potato.
4. The lawyer dropped his clients like hot potatoes once he learned he was being investigated for wrongdoing.
abandon, back down, bail out, bow out, buckle under, capitulate, cave in, cease, cede, chicken out, cry uncle, desist, drop, fold, hand over, pull out, quit, resign, stop, surrender, throw in the towel, walk out on, wash one’s hands of, yield