noun. A step-something who is held in the not-so-highest esteem.
Real citation: “About the no dishwasher thing, my mom's house doesn't have one and they ended up getting a mini protable one??? I think that's what it is anyways. I'm not sure how it works but I can ask her if you want me too, that way you'll have an option!! LOL A smaller dishwasher works for them 'cause it's only her, my step-butthead (oh, I mean step-dad, don't much care for him), and my little bro that lives there now so not really a lot of dishes.”
(Aug. 18, 2006, http://184.108.40.206/search?q=cache:HKU_kn1bZc8J:www.boxerpals.org/forums/lofiversion/index.php/t2712.html+step-butthead%27&hl=en&ct=clnk&cd=1&gl=us)
Made-up citation: “My childhood was hard. I grew up with a step-butthead, a step-buttmunch, a nimwad-in-law, a trio of chinchillas, and an angel with a broken collarbone. Want to be my girlfriend?”