“色字头上一把刀”英语怎么说？

Indulging on your lust is equivalent to hang a knife upon your head.
只好这样 不然真硬翻译99%的老外都不懂啊

Color word heads a knife

The head part of the Chinese charater "color" takes the meaning of "knife".

You may suffer from sex!
意译，都是s开头的

Eros has an inherent risk.

意译：

Eros
n.
[希神]爱神, 愿望, 性爱

Sex will kill you.