Gone, but never forgotten. Former Teen Mom OG star Farrah Abraham took to Instagram on Wednesday, May 8, to pay tribute to her late boyfriend and Sophia’s father, Derek Underwood, on what would have been his 29th birthday.

“To one very special person, I celebrate and remember you like no other. Happy birthday, Derek. I love you. May 8th — you would be 29 today. Birthdays used to be so simple,” she wrote in a heartfelt message. “You gave me that once in a lifetime love of my life everyone so deserves. You gave me so many firsts — from virginity, proms, trips, my first ring. You showed me unconditional love. You showed me what relationships are. From prom, graduation, to our only child … all the events that had happened the entire sequence was one filled with the thrill, love and loss.”

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To one very special person I celebrate and remember like no other-Happy Birthday Derek I love you, May 8th you would be 29 today, birthdays used to be so simple.You gave me that once in a lifetime love of my life everyone so deserves, you gave me so many 1st’s, from virginity, proms, trips, my first ring, you showed me unconditional love, you showed me what relationships are, from prom, graduation, to our only child…all the events that had happened the entire sequence was one filled with the thrill, love & loss. Now I share a birthday breakfast in your memory & all our best photos and your childhood photos with our daughter. I see all of your messages to me, & your written letters. Thank you for being the best loving man I know, and one of the strongest. All the memories we had. Our groups of friends & haters can’t deny our legendary times, from school, parties, summer nights & in-between. My partner in crime getting me in all the trouble – love you legend we all miss you today more then ever & so much love, memories from Sophia & I , family, friends and those who watched over the years , Happy Birthday I love & miss you, and thank you for everything you did for me❤️🎂 ( these pictures & video of sophia today made my May so blessed )

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She continued, “Now, I share a birthday breakfast in your memory and all our best photos and your childhood photos with our daughter. I see all of your messages to me and your written letters. Thank you being the best loving man I know and one of the strongest. All the memories we had. Our groups of friends and haters can’t deny our legendary times — from school, parties, summer night and in between.”

The reality TV starlet concluded the post by explaining that he lives on through her memories. “My partner in crime, getting me in all the trouble. Love you, legend. We all miss you today more than ever and so much love, memories from Sophia and I, family, friends and those who watched over the years,” she said. “Happy birthday, I love and miss you and thank you for everything you did for me. (These pictures and video of Sophia today made my May so blessed).”

Unfortunately, Derek lost control of his car while driving in Iowa on December 28, 2008. After the car skidded and flipped over, Derek and another passenger died at just 18 years old.

Even though Sophia never got to meet her dad, she still gave him a sweet shout-out on social media. “Today is my daddy Derek’s birthday! I’m sharing some little memories with all of you guys today,” the 10-year-old captioned a few photos of herself with Farrah, 27, on Instagram. “I’m so thankful for my mom being there for me in my hardest time. When I think about my dad, and I miss him so, so, so much.”

So sweet. We’re sending love to Farrah and Sophia today!

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