Justin Bieber is nothing if not persistent: A lesson his on-again/off-again girlfriend Selena Gomez (and her cellphone plan) is learning the hard way.

The sometimes couple recently called time on their relationship for the third time in six months. The latest bust-up has left Justin, 18, so upset that he’s allegedly been ringing 20-year-old Gomez incessantly with pleas to take him back.

A tattle blabbed to Hollywood Life:

“Justin’s devastated and pathetic right now. He’s calling her 100 times a day and she’s not picking up.”

Despite a holiday ski trip to Utah, things went wrong for the couple when they jetted to Mexico after the festive season.

“Their time in Mexico was much of the same for them, constant arguments and bickering. So they ended it. Selena is Justin’s first love and he’s still young enough that he desperately tries to make it work. But Selena is mature enough to just know when to end it and be realistic that it isn’t working.”

The split could explain other questionable behavior from the Biebs of late. Justin was photographed at California’s Newport Beach Hotel on Jan. 2 enjoying a suspicious-looking cigarette with his best pal, 19-year-old rapper Lil Twist. TMZ accused him smoking a “smoldering blunt.”

Written by Castina on January 7th, 2013 | Tagged as: Justin Bieber,Selena Gomez