「YY」是什么意思？

意淫。（认真地）想象一些自己希望发生，但是实际不怎么可能的事情。可以跟淫秽有关，也可以无关。

ENTo fantasize. (Seriously) imagining things that one hopes will happen but are actually not very likely. It can be related to obscenity, or it can be unrelated.