It looks like "Teen Mom OG" star Gary Shirley is keeping a big secret: he's married! The 28-year-old and his girlfriend Kristina Anderson reportedly tied the knot in September.

According to the blog The Ashley, Gary and Kristina obtained a marriage license on Sept. 28 and got married that same day. The reported newlyweds have yet to comment on the news, and details surrounding their wedding day have not been released.

This will be the first marriage for Gary and the second for Kristina, whom he shares a six-month-old daughter Emilee with. Gary was once engaged to his "Teen Mom OG" co-star Amber Portwood but the two never made it down the aisle. Gary and Amber are parents to 6-year-old Leah. According to The Ashley, Gary’s marriage may be featured on Season 5 of the MTV show, which is currently being filmed.

Even though Gary hasn’t confirmed the marriage rumors, he has been gushing about his family on social media. In April he posted a picture of him and Leah making funny faces as they waited for Kristina to give birth. And on Monday, he shared a photo of Leah wearing a mask holding Emilee, writing “My girls.”

As previously reported, Amber may be next to get married. The 25-year-old got engaged to Matt Baier, 44, earlier this year. The two are reportedly planning for an October 2016 wedding. 

Amber previously told MTV she hopes her "Teen Mom" co-stars Farrah Abraham, Maci Bookout and Catelynn Lowell will be in her wedding.

“Of course I want all the teen moms, all the girls, to be my bridesmaids," she said. "I mean, they have to be a part of it.”