For an affine space over $\mathbb{z}_2$ with $n=2^k$ we have $\binom{n}{2}=(2^{k}-1)2^{k-1}$ however there are $\frac{2^{k}(2^{k}-1)(2^{k}-2)}{24}$ 2 dimensional flats of which any pair intersect in at most two points.