To nourish a threat or be too lenient with a subordinate, only for them to cause you harm later; comparable to harboring a snake in one's bosom

An occasional display of dramatic behavior or petulance can add excitement to a romantic relationship, but overdoing it can be harmful; adapted from the proverb [[小酌怡情，大酌伤身|小酌怡情，大酌傷身|xiao3 zhuo2 yi2 qing2 da4 zhuo2 shang1 shen1]].

proverb meaning that drinking in moderation can be a pleasant social activity while overindulgence will damage one's health