Meaning:

PU is short for “paternity uncertainty,” and “值” literally means “value.” According to the parental investment theory, mothers are inclined to provide optimal care for their offspring due to the certainty of a genetic relationship. On the other hand, fathers are not so sure. Paternity uncertainty is when a putative father is uncertain of whether he is unknowingly investing in a genetically unrelated offspring. According to Chinese netizens, women high on the “PU” scale are those thought as more likely to cheat on their partners, and men high on the “PU” scale are those more likely to distrust their spouses.

Example:

A: 听说丽丽和她的土豪男朋友分手了？

Tīngshuō lìlì hé tā de tǔháo nánpéngyǒu fènshǒu le？

I’ve heard that Lili broke up with her super rich boyfriend. Is it true?

B: 是啊，那个男的虽然很有钱，但PU值太高，丽丽和闺密一起逛街吃饭都要打好几个电话报告行踪。

Shì a，nàgè nánde suīrán hěn yǒuqián，dàn PU zhí tài gāo，lìlì hé guīmì yīqǐ guàngjiē chīfàn dōu yào dǎ hǎo jǐgè diànhuà bàogào xíngzōng。

True. That man is indeed super rich, but he is very distrustful. Lili had to call in several times to report her whereabouts when she went shopping and dined out with girlfriends.