A rare condition that affects a male's ejaculatory substance color, making it come out with a yellow tint instead of a brilliant white. It's still unclear what causes yellow sperm.
Duder 1: "Whoa dude the other day I was jerking it and my spunk came out kind of yellow."
Duder 2: "No way dude! I read about this. You got yellow sperm! That's fucking gross. You should get that shit checked."