  In 2018, XMM-Newton observed the awakening in X-rays of the Be/X-ray binary
(Be/XRB) A0538-66. It showed bright and fast flares close to periastron with
properties that had never been observed in other Be/XRBs before. We report the
results from the observations of A0538-66 collected during the first all-sky
survey of eROSITA, an X-ray telescope (0.2-10 keV) on board the
Spektrum-Roentgen-Gamma (SRG) satellite. eROSITA caught two flares within one
orbital cycle at orbital phases $\phi = 0.29$ and $\phi = 0.93$ (where $\phi=0$
corresponds to periastron), with peak luminosities of $\sim 2-4 \times 10^{36}$
erg/s (0.2-10 keV) and durations of $42 \leq \Delta t_{\rm fl} \leq 5.7\times
10^4$ s. The flare observed at $\phi \approx 0.29$ shows that the neutron star
can accrete considerably far from periastron, although it is expected to be
outside of the circumstellar disk, thus providing important new information
about the plasma environment surrounding the binary system. We also report the
results from the photometric monitoring of A0538-66 carried out with the REM,
OGLE, and MACHO telescopes from January 1993 until March 2020. We found that
the two sharp peaks that characterize the orbital modulation in the optical
occur asymmetrically in the orbit, relative to the position of the donor star.
