  We revisit the phenomenology of the deep exclusive electroproduction of a
lepton pair, i.e. double deeply virtual Compton scattering (DDVCS), in view of
new experiments planned in the near future. The importance of DDVCS in the
reconstruction of generalized parton distributions (GPDs) in their full
kinematic domain is emphasized. Using Kleiss-Stirling spinor techniques, we
provide the leading order complex amplitudes for both DDVCS and Bethe-Heithler
sub-processes. Such a formulation turns out to be convenient for practical
implementation in the PARTONS framework and EpIC Monte Carlo generator that we
use in simulation studies.
