More Than Mr. Britney Spears

Sam Asghari, the pop star’s fiancé, is working on his own path to fame in a year that has thrust him into the spotlight.

LOS ANGELES — Sam Asghari is a nascent actor and erstwhile personal trainer. But this highly polite, handsome and friendly 27-year-old is better known to millions as the fiancé of a 39-year-old woman who was, for years, the biggest pop star in the world, control over whose personal life and $60 million estate was, 13 years ago, stripped from her and reassigned to her father (and a court-appointed lawyer to co-manage finances) in a controversial and secretive arrangement from which she has been forcefully and publicly trying to extricate herself; a woman who has been, for years, photographed in the regular company of no adult save Mr. Asghari, and whom he declined to acknowledge, by name or even oblique reference, as a condition of granting an interview.

That Mr. Asghari’s extremely famous fiancée, Britney Spears, is engaged to marry him is one of few details about her private life that is public knowledge. Both have said in interviews that they met in 2016 when he appeared in a music video for her single “Slumber Party” (featuring Tinashe), in the role of contemplative observer as she crawls down a banquet table to lap up what appears to be spilled milk.

Since then, the pair have shown themselves together many times on their Instagram accounts — typically engaged in a physical fitness activity, relaxing in a cloudless vacation spot, mugging to the camera at close range or some configuration of all three. The couple announced their engagement on Instagram in September (he with a photo; she with a compilation of clips in which she flashed her diamond ring to the camera).