The 32-year-old reality star hosted the lavish bash for the Cleveland Cavaliers star on his 26th birthday Monday.
Kardashian decked out her home with gold and white decorations, including balloons, streamers and a large floral table runner.
She also provided matching desserts, such as gold-frosted donuts and gold-wrapped Kit Kat bars.
"She's being shy," a friend said as they filmed Kardashian for a Snapchat video. "This is who put this whole thing together."
Kardashian was first linked to Thompson in October and enjoyed a tropical getaway to Jamaica with the NBA player in February.
She couldn't help but gush about Thompson during an interview with "The Talk" the same month.
"I'm in a really good space right now in my life," the star said. "I feel really happy and secure. I'm just in a really positive, healthy relationship."
"I actually love Cleveland. Everyone is so nice there," she added. "I love routine. It's a normal, routine life. I love to cook, so I get to cook dinner every day. It's, like, this home, family thing that I've been craving."
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