Reminds me of the old joke.
Superman is flying above metroplis, he sees Wonderwoman sunbathing naked on top of a skyscraper.
He thinks to himself, I can move so fast, I could shag her without her ever knowing, so moving at the speed of light, he whips down, does a super speed shag, and flies off again.
Wonder woman shudders "What the hell was that?" she asks
"I dont know, but my arse is killing me" said the invivisble man