Kailyn Lowry is getting a shock in Monday night’s episode of Teen Mom 2.

In a PEOPLE exclusive clip, the mother of three revealed that ex-boyfriend Jo Rivera seeking $1,000 in child support.

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“So, yesterday I was picking up Lincoln from school and I got a text from my attorney who says … let me read it to you, because my jaw hit the floor, honestly,” Lowry, 26, told to her best friend, Becky.

The MTV star began reading the text aloud: “I should let you know Mr. Rivera thinks … he can get over $1,000 a month from you. He is requesting your financial information and is moving forward on this. You should probably schedule a time to see me ASAP. His new attorney is quite insistent on his client’s rights and your obligation to pay.”

Lowry then told Becky why Rivera’s actions bothered her so much.

“So Jo filed for child support against me and wants over $1,000 a month,” she explained. “Never once did he mention to me that he was in any type of situation where he needed financial support or that he was even considering filing for child support.”

Image zoom Kailyn Lowry MTV

She continued, “I was getting child support since Isaac was maybe 8 months old. He was paying $475, which, okay let’s drop it, let’s just call it a wash. I even told him a while ago I would drop it, I just never got around to it. He was always the one to preach to me about talking things out.”

Lowry said she texted Rivera about the child support, telling him, “‘You’re really asking for child support when we have 50/50?’ He said, ‘You’re a hypocrite.'”

“I hope that Jo asks me for something so I can tell him, ‘Go f— off,'” Lowry added. “Do not come here and act like you’re my friend and hang out for a couple of minutes, don’t hold my son, don’t do anything if you’re going to be sneaky and go behind my back.”

Rivera and Lowry share one son together, 9-year-old Isaac. Lowry also has 5-year-old son Lincoln from her previous marriage to Javi Marroquin and 1-year-old son Lux with Chris Lopez.