Kailyn Lowry was among the guests at Jo Rivera's wedding to Vee Torres.
"Y'all really want me to still be bitter about Jo & Vee. We've come a long way since we were 18," Lowry, who shares 8-year-old son Isaac with Rivera, wrote.
"I couldn't ask for a better stepmom for isaac," she said of Torres. "Literally cried tears of happiness for them last night. that's fam."
Us Weekly reported Rivera married Torres in Bloomfield, N.J. Isaac and Vivi, Rivera's 2-year-old daughter with Torres, served as ring bearers during the ceremony.
"What a great wedding," the star wrote.
Lowry and Rivera were high school sweethearts who split shortly after Isaac's birth in 2010.
The ""Teen Mom 2" star described Rivera as her "best friend" in an interview with MTV News in 2017.
"I can tell him anything. I can call him, and we can switch weekends easily or if I need him to grab Isaac from school. We are so good now," she said.
"Teen Mom 2" co-stars Jenelle Evans, Chelsea Houska, Leah Messer and Briana DeJesus.