Heidi Klum celebrates teen son Henry's bittersweet 19th birthday with emotional video

Heidi Klum is celebrating a special day for one of her four children today — her oldest son, Henry Günther Ademola Dashtu Samuel, turns 19.

While it's a moment of celebration for the 51-year-old supermodel, it also comes with a bittersweet tinge, as it's Henry's first birthday since leaving the family home for college.

To mark the occasion, Heidi shared an emotional throwback of an adorable young Henry celebrating his 11th birthday with friends in school.

She may be unable to have him at home to mark the big day with family, but she certainly can share the joy with her fans. Heidi wrote alongside her video: "Yes my beautiful Henry. Happy birthday to youuuuuuuu. I love you with all my heart. Yipppppiiii happy 19th birthday."

Heidi is also a mom to daughters Leni Olumi Klum, 20 , and Lou Sulola Samuel, 14 , plus younger son Johan Riley Fyodor Taiwo Samuel, 17. She shares her four children with ex-husband Seal and now co-parents with her current husband Tom Kaulitz.

Henry graduated from high school earlier this year, with his family proudly attending the ceremony to cheer him on. "CONGRATULATIONS HENRY," she captioned a clip from his graduation ceremony . "We are all sooo proud of you. You did it my beautiful boy. College here we come! SHINE BRIGHT."

She hasn't revealed what college he's attending to maintain some privacy. His older sister Leni is in New York City studying interior design while also modeling and attending high-profile events with her mother.

MORE: Heidi Klum reveals special glimpse of new Halloween costume that will get fans talking

Heidi and Seal effectively co-parent their four kids and maintain strong bonds with them, although they've also come to really love Tom as a father figure as well. In fact, the America's Got Talent judge revealed recently that they actually helped him propose back in 2018 .

© Instagram

"The sweetest thing that my partner has done for me is that he asked my kids first if he could ask for my hand," she sweetly told People . "So he kind of was in cahoots with my kids."

MORE: Heidi Klum celebrates double dose of joyful news with husband Tom Kaulitz

The Germany's Next Topmodel host explained that they all got together to plan, with Tom popping the question just months after they first started dating, and the four kids were an integral part of their romance.

© Getty Images

"They figured out how they were going to do it and then they all surprised me on Christmas morning six years ago. I thought that was so nice that he involved my kids."

MORE: We ranked Heidi Klum's best Halloween costumes of all time

She also told Glamour in a different interview that her kids have a "thick skin," specifically pointing out Leni and discussing her foray into modeling . "She wanted to start at the age of 13, and I let her at 16. At 16, kids in the USA can drive, so it was okay for me to let Leni model – if that's what she wanted," she continued. "We discuss everything, I check her offers. I help her choose outfits for events. She usually chooses the outfit I advised her against."

© Getty Images

"I made it clear to her from the start that, as my daughter, she would be a target for the public. Many people will think she's cute, others will think she's stupid. Just because she's my daughter. People who don't like me might automatically not like her either. She must have a thick skin, but my children have that."