What starts with "s" and ends with "erm"? SuperM.
This means both "matrix" and "master" so take out the "u" and then you just get "master". When you think of sperm, you think of porn. If you're a master at something, you're also a star at it. So you get porn star.
Listen up, buttercup. The joke plays on the letters "s," "u," "p," "e," "r," and "m" to reference "sperm" and then "porn". The joke tries to connect being a "master" at something and being a "star" at it. It's not even funny, and you probably think it is because you wear velcro shoes, don't you?
Gwen
Yur frickin' smart
J
That joke sucked ass dude