They know from experience!

Teen Mom's Amber Portwood and Catelynn Lowell are setting the record straight when it comes to truly safe sex.

Both Portwood, 20, and Lowell, 19 famously chronicled their unplanned pregnancies on the first season of MTV's hit. Portwood and her on-and-off beau Gary Shirley gave birth to their daughter Leah Leann in November 2008. and have struggled to provide a stable home. Lowell and her boyfriend, Tyler Baltierra, welcomed their daughter Carolyn "Carly" Elizabeth in May 2009; the young parents decided to put their daughter up for adoption and later struggle with that choice.

In a new MTV special Top 10 Most Outrageous Sex Myths airing Tuesday at 8:30 p.m., the duo get brutally honest about a sex myth no one should believe.

Watch the clip now.