Caitlyn Jenner -- My First Father's Day!!!

Caitlyn Jenner celebrated her first Father's Day with her children, and there's a lot more significance than you think.

Caitlyn's kids from all 3 ex-wives came together for the shindig at her Malibu house. Of course, it's the first time she's celebrated the holiday as a woman. Caitlyn has told her kids she will always be their dad.

But there's more. Caitlyn never celebrated Father's Day with all her kids. Kris organized Father's Day events, but the boys and Cassandra rarely went.

Now that there are no wives to organize Father's Day parties, Caitlyn -- like many single dads -- is left to her own devices. We're told Sunday's festivities were initiated by Caitlyn.

Interesting some of the Caitlyn's sons are celebrating with her daughters ... they don't really socialize together.

Whatever ... hopefully a good time was had by all.