"Teen Mom 3" alum Alex Sekella is engaged to be married. The 25-year-old took to Instagram this week after saying "yes" to boyfriend Tim Peters. Sekella shared a collage of photos of herself and Peters around their Christmas tree. She also showed off her engagement ring, which features a round center stone. "A few days ago this incredible man asked me to be his wife. @timpeters24 #happilyeverafter," the star captioned the post. Us Weekly said Sekella and Peters have been dating more than four years. The pair celebrated their four-year anniversary as a couple in April. "Another year added to what I hope is many more to come. Love you Happy Anniversary. @timpeters24," Sekella captioned a collage of photos at the time. Sekella came to fame on the MTV series "16 & Pregnant" before starring on "Teen Mom 3." She is parent to 7-year-old daughter Arabella with her ex-boyfriend Matt McCann. "Today is Arabella's Big birthday. I can't believe she is 7 but it doesn't seem so long ago when this angel entered the world," the star wrote on Arabella's birthday in July.