No it's not. Its slightly towards the f.
So cheetah wins!
It's not.
You are mistaken because the sex ratio of living people in western countries is towards the f.
That's only because females live longer, and the birth rate is low in those countries.
All over the world the natural sex ratio at birth is towards the m, in every country.
That means that, in a big enough geographic zone, for a long enough span of time, the number of males that have ever lived there is higher than the number of females that have lived there.
So the average number of heterosexual partners is higher for females than for males.