"Size matters" is no longer funny. It has been unfunny since the mid-1980s. People born when we first elbow-nudged each other, waggled our eyebrows, and said, "Size matters! Huh?! Huh?!? Get it?!" may now legally buy alcoholic beverages. 
 
Saying or writing it will not add to your reputation as a wit. All it says now is you can't stop comparing things to penises.  
 
Stop it. 

Posted by: Fritz Anderson