Timothée Chalamet is girlfriend Kylie Jenner’s biggest fan.

The actor shared a mirror selfie on his Instagram Story Wednesday, wearing a pair of cropped sweatpants and a white tank. Chalamet slipped into white Adidas sneakers ($100) and added a Nahmias baseball cap to finish off his look.

The capri pants featured a tiny “K” embroidered by the pocket, appearing to be the Venice Long Shorts ($120) from his ladylove’s clothing company, Khy.

The shorts reach past his knees and are technically unisex, making it possible that the couple, who have been together for more than three years, actually share the piece.

Chalamet, 30, is in NYC this week as the New York Knicks take on the Cleveland Cavaliers in the NBA Eastern Conference.

He attended Tuesday’s game solo — but Jenner showed her approval, commenting a flirty message on Page Six’s TikTok video of the “Dune” star’s arrival.

Jenner herself has been to multiple Knicks games in support of her man, diligently wearing blue and orange courtside.

As for her fashion brand, the makeup mogul “refreshed” Khy last month, releasing new, more pared-down products at her own hands rather than in partnership with established designers as in the past.

And she’s tapped other loved ones as of late, with daughter Stormi Webster modeling some Khy goodies on social media.