A mixed mega sour is a "sweet" that is VERY sour, and is bound to make all but the most courageous puke out of their eyeballs. It is a multi-coloured ball-sweet that the makers expect people to eat. The following example is actually a true story, and it all happened word for word.
My brother warned me about these... I didn't listen, and proceeded to eat one. The following example is what happened then, me being guy number 1, a friend is guy number 2.
Guy number 1: Holy SHIT. That sweet was DISGUSTING. 'mixed mega sours' Very, very accurate description. Mixed into a pile of shit and puke, and then coloured by an ill squirrel's piss.
Guy number 2: I don't see the problem
Guy number 1: I just ate a multi-coloured ball of shit.
Guy number 2: Ah