Mariah Yeater, the 20-year-old woman who claims she slept with Justin Bieber, is showing off her pierced and tatted up body in new, scandalous photos.

Yeater says she and Bieber had sex following his concert at the Staples Center on October 25th of last year ... resulting in the birth of her son, Tristyn Anthony Markhouse Yeater.

In a California courtroom under oath, Yeater told a judge:

    "On July 6, 2011, I gave birth to a baby boy. That was exactly 36 weeks and two days after the sexual encounter with Justin Bieber. Based upon the timing as well as the fact there were no other possible men that I had sex with that could be the father of this baby, I believe that Justin Bieber is in fact the father of my baby."

So after seeing some of these photos, do you see Bieber being attracted to Yeater? She doesn't look ANYTHING like his current girlfriend Selena Gomez.

See more photos of Mariah in our gallery below.