It's Catelynn Lowell's Fiancé, Tyler Baltierra!
Tyler's all grown up, ladies! It's almost hard to believe he's the same guy we met during Season 1 of MTV's 16 and Pregnant back in 2009.
Catelynn's also been hitting the gym hard in recent months, most likely in preparation for their upcoming summer wedding. By July, these two will look hotter than the couple on the top of the cake!
Are you impressed with Tyler's transformation? Tell us below and click here to play more Teen Mom "Guess Who?"