PopUps: Britney Spears' BF Sam Asghari Says He Wants 'to be a Young Dad'

Fitness trainer Sam Asghari is opening up about his personal life, saying he's ready to be a father.

Speaking with Forbes, Asghari, 27, who has been dating Britney Spears for four years, discussed his future with the pop star.

"I want to take my relationship to the next step," he said. "I don't mind becoming a father. I want to be a young dad."

Asghari met Spears, 39, who has two teen sons with her ex-husband, Kevin Federline, on the set of her "Slumber Party" music video; he almost didn't meat the "Hold It Against Me" singer, however.

"I was already known on a music video, so I didn't want to do another music video because of that," he said. "My friend called me and said, 'I need you to be on it. Trust me, you want to show up.' I didn't know who was shooting. It was a secret project. So I showed up because of my friend. I showed up...and everything kicked off from there."

Asghari also talked about Spears' infamous Instagram posts, which he often appears in.

"I do it authentically. Whether it's an occasion or a photo or video that I like, I post it on social media, but I'm very careful when it comes to my personal life. I'm very protective of that," he said. "At the same time, I think it's very healthy what you appreciate from your personal life and what you're proud of."

Just last week, Spears shared a video on Instagram of the two of them recreating the strings of her song "Toxic" by dragging their faces across the glass doors in their shower.

Spears was the subject of a New York Times documentary "Framing Britney Spears," which examined her career and the way in which the media and tabloids treated her.

This story is part of our special report: "PopUps". Want to read more? Here's the full list.