Leah Messer opens up about her custody battle for her twin daughters in the new issue of Us Weekly.

“It was like a slap in the face.” That’s how Leah Messer describes the moment she learned her ex-husband Corey Simms had been awarded primary custody of their 5-year-old twins, Aliannah and Aleeah. On Oct. 7, a West Virginia judge ruled that Simms, 26, would have the girls Monday through Friday, leaving the Teen Mom 2 star, 23, with just weekends.

In a no-holds-barred interview in the new issue of Us Weekly, Messer opens up about how she’s coping — and what she’s doing to fight back. She reveals the custody swap occurred after an Aug. 24 hearing when utility company technician Simms accused her of not getting the girls to kindergarten on time. “Leah just wasn’t getting them to school,” explains a source. “They were missing and they were tardy.”

But Messer — who completed a 30-day stay at a treatment facility for anxiety and depression this June — insists to Us that’s simply not true. While she cops to one tardy, she says the rest never happened. To challenge them, she set up an Oct. 19 school-board meeting.

“I talked to the superintendent,” she adds, “and I’m sending them the [time-stamped] pictures I took to prove the girls were not tardy. They’re going to take them off.” (School officials could not be reached for comment.)

For the mom of three (she also has 2-year-old Adalynn with ex-husband Jeremy Calvert), that’s just the first step. She filed a motion to reconsider the custody change and hopes to eventually share 50/50 custody with Simms, who’s expecting his third daughter, Remi, with wife Miranda this January.

“I feel like they should have both of us in their lives,” she says of her twin daughters, adding that their well-being is her only concern. “At the end of the day, my kids are going to be happy, and I don’t care what I have to do to make them happy.”

For more details on Messer’s plans for her twin girls — and why she thinks Simms wants custody — pick up the latest issue of Us Weekly, on newsstands now!

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