I lost my dad a few years ago at 59 years old. He only just met my youngest son before the cancer took him from us. He was the baddest mf’r on the planet and demanded respect from us kids. It worked for me, it’ll work for my kids. We never really made it to being friends, but we had an understanding.
FWIW - I’m 35, and I’d give anything to tell my dad I love him. I take every opportunity to remind my kids how much I cherish them. If I had 1 recommendation for you guys, don’t be shy, tell those kids you love them. Make the phone call. Make time.