Chelsea Houska turns 29 on Aug. 29, and she has a lot to celebrate! The birthday girl, who starred on MTV’s 16 & Pregnant and has been on Teen Mom 2 since 2011, is currently pregnant with her fourth child. This will be her third baby with her husband, Cole DeBoer, while she also shares a daughter, Aubree, with her ex, Adam Lind. Chelsea and Cole’s relationship is a fan-favorite for Teen Mom viewers, and we rounded up some of their best Instagram pics ever.