  The elliptic flow ($v_{2}$) of (anti-)$^{3}$He is measured in Pb-Pb
collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV in the transverse-momentum
($p_{\rm{T}}$) range of 2-6 GeV/$c$ for the centrality classes 0-20%, 20-40%,
and 40-60% using the event-plane method. This measurement is compared to that
of pions, kaons, and protons at the same center-of-mass energy. A clear mass
ordering is observed at low $p_{\rm{T}}$, as expected from relativistic
hydrodynamics. The violation of the scaling of $v_{2}$ with the number of
constituent quarks at low $p_{\rm{T}}$, already observed for identified hadrons
and deuterons at LHC energies, is confirmed also for (anti-)$^{3}$He. The
elliptic flow of (anti-)$^{3}$He is underestimated by the Blast-Wave model and
overestimated by a simple coalescence approach based on nucleon scaling. The
elliptic flow of (anti-)$^{3}$He measured in the centrality classes 0-20% and
20-40% is well described by a more sophisticated coalescence model where the
phase-space distributions of protons and neutrons are generated using the
iEBE-VISHNU hybrid model with AMPT initial conditions.
