premature ejac-o-lantern
To become overly excited about Halloween and making a jack-o-lantern too far in advance, thus allowing the pumpkin to rot and leave behind an unexpected mess that is embarassing to clean up. Usually happens once a year.
"Hey man, did you hear about Kory?" "I guess he premature ejac-o-lanterned all over the kitchen counter. He had to hurry and clean it up before his roommates got home."