Gossip Girl: Kelly Rutherford celebrates Matthew Settle's birthday with sweet post 

Every unforgettable moment, every gorgeous dress.

Rufus and Lily shippers, you might want to sit down for this one.

have mostly gone their separate ways — but two have remained adorably close, and our teenage hearts are bursting at the seams.

Kelly Rutherford took to Instagram on Sunday to wish her former costar and good friend Matthew Settle a happy birthday, sharing a photo of them embracing sweetly.

Happy Birthday to my handsome soulful friend @matthew_settle. I love you and think the world of you. As an actor father and friend. Sending you so much love today and everyday. 🎂 ( as you can see I have a really tough time showing my affection for this human 😉)

“Happy Birthday to my handsome soulful friend @matthew_settle,” she captioned the shot. “I love you and think the world of you. As an actor, father and friend. Sending you so much love today and everyday.”

“As you can see I have a really tough time showing my affection for this human,” she quipped.

Rutherford, 48, played Lily (mother to Blake Lively‘s Serena van der Woodsen) on the beloved CW drama, which concluded in 2012. Settle, 48, played Dan Humphrey’s (Penn Badgley) dad Rufus.

Though Serena and Dan’s relationship dominated the plot, Lily and Rufus’ own love story also captured the hearts of viewers — and sparked rumors of an off-screen romance, as well.

In 2010, the two leaned heavily on each other in the wake of Settle’s separation from his wife, which coincided with Rutherford’s own divorce. Speaking to PEOPLE at the time, Rutherford said Settle had been “really supportive.”

“He’s a great friend and I really appreciate that,” she said.

“We’re good friends,” Settle added. “Kelly and I have a lot in common because we are supporting each other at this time in our lives.”

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