Lowry, 25, and Houska, 26, reacted Monday on Twitter after Evans, their longtime co-star, accused them of "defamation of character, libel and slander," according to documents obtained by Radar Online.
"How does one get a cease & desist from someone they don't care to talk about... & if i did, it's my opinion," Lowry wrote, adding a crying tears of laughter emoji. "#hijenelle #byejenelle."
"I just got a cease and desist from Jenelle and David," Houska added, referencing Evans and her husband, David Eason. "So there's that lolll. #idonteventalkaboutyou."
Evans claimed in the letter that Lowry and Houska have disparaged her and Eason on social media. She married Eason at their home in North Carolina in September after getting engaged in February.
"You are hereby warned and notified to cease and desist making false and defamatory statements regarding Mr. and Mrs. Eason and their family affairs," the letter reads. "It has come to our attention that false and defamatory statements disparaging Mr. and Mrs. Eason's character have been made by you via numerous social media postings."
Evans said she will pursue legal action if Lowry and Houska fail to cease their alleged behavior. The trio of stars, who came to fame on the MTV series 16 & Pregnant, have clashed off and on during their time on Teen Mom 2.