The former MLB star took to Instagram on April 21 to celebrate his daughter Ella's 13th birthday with an emotional slideshow featuring the family's most memorable moments.
Alex, who played as number 13 on the New York Yankees, captioned the slideshow, "13. Wow. That number has meant a lot to me over the years, but today, it's even more special than ever. I just can't believe my Ella Bella turns 13 today. My baby girl is officially a teenager!!"
He continued, "Ella - everyday you amaze me more than I could have ever imagined. You are smart, mature, talented, caring, and funny. I am so proud of the young woman you are becoming and so lucky and grateful to be your dad. I love you so much."
The slideshow featured plenty of photos of Alex with Ella and her sister Natasha, 16, however, he made sure to include J.Lo in the mix as well. Around the 1:05 mark, the athlete shared a sweet, never-before-seen snapshot of the Hustlers star with Ella.
Alex and Jennifer confirmed their split on April 15 with a joint statement, which came weeks after they denied rumors that they had broken up, instead saying that they were merely "working on some things." As the couple were together for four years, the two had blended their family, which also included J.Lo's 13-year-old twins Max and Emme with ex-husband Marc Anthony.
"We have realized we are better as friends and look forward to remaining so," the former couple said in their statement. "We will continue to work together and support each other on our shared businesses and projects."
They added "wish the best for each other and one another's children" and that "out of respect for them, the only other comment we have is to say is thank you to everyone who has sent kind words and support."
Prior to their breakup, the two often shared photos of their big family, including one of video Jennifer posted to Instagram of the crew counting down to the New Year back in January.
While how they celebrate will likely change now that Alex and Jennifer are over, J.Lo certainly was a big enough part of Ella's life to warrant being part of the 13 year old's big day.