Life & Style has learned that Selena Gomez has set some ground rules for Justin Bieber in order to keep their two-year, on-again, off-again relationship going strong.

“Selena laid down the law about what Justin must do to make her happy,” a member of Justin’s inner circle tells the new issue of Life & Style, on newsstands now. “She was very specific and told him that if he messes up, it will be over.”
The most important rule to make her happy is clear: Stay away from other women.

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“Selena doesn’t want to share him,” the insider reveals to Life & Style. The final straw to their strained relationship came when Justin got cozy with model Barbara Palvin at the Victoria’s Secret Fashion Show in NYC on Nov. 7.

Following the very publicized incident, “She [Selena] said he can’t have girls or models back to his hotel room,” a second insider tells Life & Style.

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In addition to Selena tightening the reins on who Justin spends time with — one of them has to be her! “They have a two-week rule — they won’t go longer than that without seeing each other,” the source dishes. “That means going on dates, walking on the beach, going on ice cream runs and just being kids.”
Selena believes they are on the mend thanks to her guidelines, says the source.
For more on Selena & Justin, pick up this week’s of Life & Style, on newsstands now.