The question of the day is what do you do when your father becomes a woman? Not a situation you encounter every day. But it was the reality for 30-something Brandon Jenner when in 2015, Bruce Jenner became singleton Caitlyn Jenner. Well, Brandon celebrated his father's "victory". His younger brother Brody Jenner, was not so relaxed.

Brandon and Brody are Caitlyn's sons with his second wife Linda Thompson. She is famous for having been a beauty queen and for having been the long-time 1970s girlfriend of Elvis Presley. In fact, she and Elvis watched Bruce win his Olympic Gold Medal while lounging in Elvis' bed.

Brandon didn't see much of his dad when he was growing up, as Bruce left the family in 1984 with a view to transitioning into a woman. It kind of freaked Linda out, as you might expect. It essentially meant that her sons lost their father.

Here's what we know about Brandon's childhood without a father and how he celebrated Caitlyn's transition, reconnecting with her in a big way.

Honey, I Want To Be A Woman

Apparently, then-Bruce told Linda that pretty much upfront. They were married in 1981, with Brandon coming along that year and Brody a couple of years later. But by 1984, then-Bruce announced his intentions of leaving to transition into a woman. His sons were far too young to understand, but as we said, it kind of did a number on Linda.

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Well, Brandon grew up to be a handsome, glass half-full kind of guy. He's done some reality TV, like 2005's The Princes of Malibu and (of course) a few Keeping Up With the Kardashians episodes. But these days, the singer/songwriter is focusing on his music and his twin sons, Sam and Bo.

Growing Up Without A Dad

Brandon wrote a chapter on his relationship with Bruce/Caitlyn in a recently published book entitled To Me, He Was Just Dad: Stories of Growing Up with Famous Fathers. It's a compilation of the stories of men and women who have had famous fathers.

Brandon wrote that he only saw then-Bruce Jenner about half a dozen times over seventeen years.

According to micky.com, he has said: “I didn’t see my father more than half a dozen times between the ages eight and twenty-five."

And when they did connect after Bruce's marriage to Kris Jenner in 1991, he said meetings felt more like photo-ops than bonding. After that, Brandon tended to stay away because he felt uncomfortable with the Kardashian lifestyle and dynamic.

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"I didn't want to be a part of their dynamic," he has said.

And that meant Brandon essentially grew up without a father. But he seems cool with it. Unlike his younger brother Brody (who was married to Kaitlynn Carter of Miley Cyrus fame), who resents his father's absence, Brandon understands what his dad was going through.

In To Me He Was Just Dad, Brandon wrote: "My father spent the first 65 years of her life trying to avoid answering the question, ‘How are you doing?' and because of that, she didn't ask it often, either. And though I understand that she avoided the question because the answer would have laid bare too many struggles, it made my relationship with her challenging."

Because then-Bruce built a protective wall around himself, he remained distant from Brandon and Brody for much of their lives.

Brandon summed up the lack of a relationship with his father when he wrote: "People connect with each other through vulnerability, and you can only get someone to open up to you if you are willing to be vulnerable yourself. Because she was shielding something so important from herself, Dad remained distant for much of my life."

2015: From Bruce To Caitlyn

Brandon says that he was thrilled when his father announced to the world that he was becoming Caitlyn. Unlike Brody, Brandon was very supportive.

And these days? What is his relationship with mega-rich Caitlyn Jenner like?

RELATED: Here's How Much Caitlyn Jenner Is Worth Today

With genuine enthusiasm, he says, "It's great. It's great. It's really good... We're closer than ever."

Apparently, Brandon and Caitlyn are both race car enthusiasts. And when they are zooming around a track somewhere, they bond over their mutual love of flying.

Says Brandon: “We do fly a lot because we’re both pilots, so we like to go and fly. We’ve got a little old plane that we can go and jump in and fly around and look for different airports to go to and then go have lunch, and stuff like that. So, we do a lot of that.”

And Caitlyn takes an interest in Brandon's career, helping him promote his music.

But still, Brandon remembers the time that his dad gave him a $250 bike for his 8th birthday. The little boy was thrilled until then-Bruce told him he expected him to pay him back every penny it cost. Well, as Brandon would say, nobody's perfect.

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