Kids ... they grow up so fast, don't they?

According to 'HollywoodLife,' 17-year-old Kylie Jenner can't wait until she turns 18 so she can officially date older men — like 24-year-old rapper Tyga — without them looking like cradle robbers.

Although they claim to be "just friends," Kylie and Tyga have been spotted on several dinner dates in public and most recently, attended a children's hospital together. If the alleged couple is trying to keep their relationship quiet, they're doing a really bad job at it.

Tyga [pictured left] and Kylie [pictured right] pose with a patient at the children's hospital. (Photo Credit: Getty Images)

"She has told her sisters many times, ‘I can’t wait to be 18. The guys my age are lame and don’t know how to treat me like [Tyga] does. He’s so fine and a perfect gentleman,'” the source said.

The reality star's 18th birthday isn't exactly around the corner. Tyga's going to have to wait a whopping 230 days (her birthday's August 10) until his rumored lady is of legal age.

Sources say she'll make their relationship official on her 18th birthday, but let's see if he's still in the picture by the time next summer rolls around!