  The Lightest Supersymmetric Particle (LSP) is generally regarded as higgsino
in focus point supersymmetry (SUSY). Under such circumstance it leads to
bileptino LSP when the MSSM is extended by $U(1)_{B-L}$ gauge group within the
framework of Double Focus Point (DFP) supersymmetry. The bileptino is a copy of
higgsino whose partner, bilepton, is used to break $U(1)_{B-L}$ gauge symmetry
spontaneously. Such scenario, however, is not favored by direct detection since
it leads to unacceptable spin-independent cross section when one requires
correct self-scattering cross section. We point out that is not necessarily the
case even in the presence of light $Z^{\prime}$. The right-handed sneutrino in
this model acts as LSP in most of parameter space for non-vanishing soft
trilinear coupling $T_{\eta}$. It is thus consistent of the requirement of DFP
SUSY without involving any direct detection issue. The corrected relic
abundance could be achieved via sneutrino annihilate into pair of bilepton
which also serve as light mediator in Self-Interacting Dark Matter (SIDM).
Moreover, stringent constraint comes from CMB anisotropies can be evaded by
considering retarded decay of right-handed neutrinos. We further stress the
need for a large soft trilinear term $T_{\eta}$ in order to generate desirable
self-scattering cross section $\sigma/m_{\tilde\nu_R}$ with moderate Yukawa
coupling $Y_{\eta}$. The numerical calculation illustrates that SIDM is
reliable in our model from the scales of dwarf galaxy to galaxy cluster.
