Love is a science. Not convinced? Take it up with Karlie Kloss.
The supermodel declared her love for longtime boyfriend Joshua Kushner this week in the form of some scientific poetry: "My atoms love your atoms. It's chemistry," she wrote on Instagram, quoting poet Atticus.
"Happy birthday to my best friend and partner in crime," she continued. "The past 5 years of our adventures together have been some of the best memories of my life. I love you @joshuakushner."
Joshua is the younger brother of Jared Kushner, son-and-law and adviser to President Donald Trump. He and Ivanka Trump were already married when Karlie and Joshua began dating in 2012.
My atoms love your atoms, It's chemistry. - @atticuspoetry ❤️🤓🎂🍪❤️ Happy birthday to my best friend and partner in crime. The past 5 years of our adventures together have been some of the best memories of my life. I love you @joshuakushner
A post shared by Karlie Kloss (@karliekloss) on Jun 12, 2017 at 6:12pm PDT
After five years together, many have speculated that marriage is on the horizon for Karlie and Joshua. While he's of typical marriage age -- 32 -- Karlie is only 24, which may be why they're taking things slow.
Karlie, a computer science activist, and Harvard Business School grad Joshua make for a not only attractive, but super-smart pair: In 2015, Joshua and Jared co-founded a tech platform that helps clients invest in real estate. The company has since raised more than $250 million in capital.
That same year, Karlie created a scholarship fund called "Kode with Klossy" benefiting girls interested in computer science and software engineering.
Although their relationship is no secret, the couple keeps a relatively low profile, only occasionally sharing photos of each other on social media. Joshua did post a faraway shot of his girlfriend in an unidentified (but exotic-looking) location on his birthday.
See photos of Karlie Kloss through the years