Tyler and Catelynn starred together on the MTV series 16 and Pregnant, before going on to appear in spin-off Teen Mom, and it's fair to say they've had their fair share of ups and downs over the past nine years.
In 2009, while filming for MTV, Catelynn gave birth to their first child together - a daughter called Carly - however they decided it was in the best interest of their daughter to give her up for adoption.
The couple are still in contact with her and recently Catelynn revealed that she and Tyler are ready for another baby, now they are older and financially stable.
Marking their anniversary, Tyler tweeted: "It's been the best 9 years of my life with @CatelynnLowell HAPPY ANNIVERSARY BABE! Love you more than words can explain #MiddleSchoolSweet."
Catelynn added: "These past nine years have been the best years of my life! I get to spend it with my babe my best friend my soul mate!"
Meanwhile, Tyler has also taken to Instagram to show off a rather large tattoo of Batman, which has been inked down the top half of his right arm.
It's pretty mega and shows the cartoon character standing in his cape with his head down, as a colony of bats fly overhead.
Tyler told his followers: "'It's not who your are underneath it's what you do that defines you' - Batman Begins #Tattoo #FinalProduct #WhyDoWeFall?"
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