I'm an idiot. The second one, "Wu Yao Zhou" is another way of saying 'I'm going', though it is the former that is used in the context of sex. 'I'm coming' should be 'Wao lai."

And you'd be surprised, because you know they are not the first words I think off when people say, 'Oh, and what do say durign sex." My poor virgin mind was all, 'but how can they sayd that?!"