  Short distance physics involving virtual top and charm quarks contributes to
$\mu^+$ (and $\mu^-$) polarization in the decay $K^+ \rightarrow \pi^+ \mu^+
\mu^-$. Measurement of the parity violating asymmetry $(\Gamma_R -
\Gamma_L)/(\Gamma_R + \Gamma_L)$, where $\Gamma_R$ and $\Gamma_L$ are the rates
to produce right and left-handed $\mu^+$, may provide valuable information on
the unitarity triangle. The parity violating asymmetry also gets a contribution
from Feynman diagrams with two photon intermediate states. We estimate this two
photon contribution to the asymmetry and discuss briefly the two photon
contribution to time reversal odd asymmetries that involve both the $\mu^+$ and
$\mu^-$ polarizations.
