Chimps are typically thought of as vegetarians, but during the mating season, 65% of their diet is comprised of meat, the females needing the extra protein to breed.
Females have been observed begging males eating meat for some. The males offer it to them, in exchange for first, yup, sex.
Even runtier low ranking males with normally hardly a chance can manage to seduce females with a chunk of meat, which they will 'casually' display purposely for such.
Given the similarities between humans and chimps, yes, it truly is the oldest profession,,,