  We are monitoring established and putative redback millisecond pulsars (MSPs)
in time-series photometry, repeatedly covering their 5-6 hr orbital light
curves in $r^{\prime}$ or $R$. On timescales of months, PSR J1048+2339 and XMMU
J083850.38$-$282756.8 exhibit similar variability of $\approx0.3$ mag on the
heated side of the companion star. However, the heating light curve is rarely
symmetric, suggesting that the intrabinary shock generated by the pulsar wind
is skewed in addition to being variable, or that changing magnetic fields
intrinsic to the companion channel the pulsar wind. In addition to this
variable heating, there are long-lived flaring states that increase the
brightness by an additional 0.5 mag, with variability on $\approx10$ minute
timescales. These flares also appear to originate on the heated side of the
companion, while the "night"-side brightness remains relatively stable.
Somewhat less active, PSR J1628$-$3205 has an optical light curve that is
dominated by tidal distortion (ellipsoidal modulation), although it too shows
evidence of variable and asymmetric heating due to shifting magnetic fields or
migrating star spots. These effects frustrate any effort to derive system
parameters such as inclination angle and Roche-lobe filling factor from optical
light curves of redback MSPs. We also report on two Chandra X-ray observations
of PSR J1048+2339 that show strong orbital modulation, possibly due to beaming
along the intrabinary shock, and a third observation that is dominated by
flaring. The peak flare luminosity in the 0.3-8 keV band is $\approx12\%$ of
the pulsar's spin-down power, which may require magnetic reconnection. None of
these three systems has yet shown a transition back to an accreting state.
