An impression of a man during the lead up to and act ejaculation. Can be based on personal experience OR simply be how you imagine a dude might look/sound when jizzing.
"OMG, when he cums he sounds like a dolphin with bronchitis, let me do a jizzpression."
"Check out this link, Jon Stewart does a great jizzpression of congressman Randy Weber."
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi