Justin Bieber — Pint-sized Trespassers in Pool Party Confrontation

EXCLUSIVE

Justin Bieber lost it with 2 young fans, chewing them out and taking one of their cellphones … but he was more than justified.

We’re told a 12-year-ancient Belieber decided to celebrate her birthday with a friend last Saturday by sneaking onto Justin‘s estate.

The girls found an opening in the form of an open gate, went inside and came face…