A wet burger is any sort of canned or bottled beer. Wet burgers are generally enjoyed cold, and can be quite refreshing.
"I'm going to the 'fridge, do you want anything?"
"Yeah, hook me up with a wet burger!"
A dripping wet hunk of woman beef.
"I saw this chick yeah, I was so turned on by her wet burger. I wanted to rub boob lube right in her spinal vaginal."