Inside Jared Leto's Private Romance with Valery Kaufman — They've Been 'Off and On' for Years

Jared Leto and model Valery Kaufman are closer than ever.

Days after the two were spotted hiking, a photographer source tells PEOPLE in this week's issue the Oscar-winning actor, 48, and the model, 26, have known each other since 2015.

"They initially seemed to be friends," says the source. "They would meet up with groups of people and all hangout. They didn't go on solo dates."

Things have changed, however.

"Over the years, things seem to have turned romantic," the source continues. "They have been off and on now for a few years, but seem to spend more time together lately."

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Leto has already introduced Kaufman, who is Russian, to his mother, Constance Leto, with the source saying, "Valery even hung out with Jared's mom earlier this year."

Kaufman celebrated her 26th birthday on May 30, sharing a childhood photograph of herself on Instagram with the caption, “My day 🎉.”

The two were spotted together in New York City as far back as June 2015 when they went shopping for groceries while taking a stroll through the city.

Leto has kept his personal life private, cheekily teasing fans by flirting with several A-list stars while he was on the awards circuit for his performance in 2013's Dallas Buyers Club.

The actor, who is also the frontman for the band Thirty Seconds to Mars, notably made a friendship with fellow Oscar winner Lupita Nyong'o, giving her a shoutout at the 2014 Independent Spirit Awards by thanking "my future ex-wife, Lupita" and adding, "I'm thinking about you."

Nyong'o touched on their friendship in Net-a-Porter‘s weekly digital magazine PorterEdit in March 2019, crediting Leto with helping her balance the fame that came after 12 Years a Slave.

"Jared Leto, he’s still on speed dial, because we were on that [Oscar campaign] journey together and he’s so embracing of me," the actress said at the time. "There was an intimacy that grew from that, that goes beyond the dating rumors, beyond all that."