Any woman in a relationship (usually marriage) with a man having one or more children from his last partnership. As far as getting along with dads new mate some step-kid's do and some step-kid's don't. Bottom line is that this woman wants to be with the guy so much that she is willing to step-up to the situation.
A group of young-adult's are having a discussion about their parent's and one says " You guy's who's folk's are still together are fuckin' lucky...my step-mom is a BYATCH, always acting like my mom and shit." Someone else says, " My step-mom is awesome, she don't make me do nuthin' and I ain't neva' seen my dad happier."
A woman whom has stepped into your life without caution and once she's been fucking around with your dad for about 2 weeks she thinks she owns him and wants you out of the picture. Basically, a fucking step mom is a wannabe mom, bitch, whore and someone who wants YOU out of the picture, and this cunt always gets her way...
Daughter: Daddy can I have some ice cream?
Dad: Um, I gues--
Step-Mom (Dad's Girlfriend): HELL NO!!!!!! YOUR FAT ENOUGH AS IT IS YOU LIL BTCH CUNT WHORE!!!