Similar to a cougar but as teenagers. Cheetah Sluts are often just feminine or vegan men who have very outlandish theatre or dancer qualities (like the hit moive Cheetah Girls starring Raven Simone). They often have many freckles, representing the the spots on a cheetahs skin.
Nate is being such a cheetah slut he keeps on performing his monolougue for the eigth grader.
Doug needs to realize that being a Cheetah Slut is never gonna get him into dance acadamy.