  We constrain the true spin-orbit alignment of the KOI-89 system by
numerically fitting the two \emph{Kepler} photometric lightcurves produced by
transiting planets KOI-89.01 and KOI-89.02. The two planets have periods of
84.69 days and 207.58 days, respectively. We find that the two bodies are
low-density giant planets with radii $0.45 \pm 0.03~\mathrm{R_{jup}}$ and $0.43
\pm 0.05~\mathrm{R_{jup}}$ and spin-orbit misalignments $72^{\circ} \pm
3^\circ$ and $73^{\circ+11}_{-5}$, respectively. Via dynamic stability tests we
demonstrate the general trend of higher system stability with the two planets
close to mutual alignment and estimate their coalignment angle to $20^\circ \pm
20^\circ$ -- i.e. the planets are misaligned with the star but may be aligned
with each other. From these results, we limit KOI-89's misalignment mechanisms
to star-disk-binary interactions, disk warping via planet-disk interactions,
planet-planet scattering, Kozai resonance, or internal gravity waves.
