  We study the effects of the identical leptons in the final state of the
$B^+\to \ell^+ \ell^- \ell^+\bar\nu_{\ell}$ decay. The amplitude of the process
is described by the same form factors as the amplitude of the ${B\to \ell \ell
\ell'\bar\nu'_{\ell}}$ decay for non-identical leptons in the final state.
However, the differential distributions are strongly different, as the ${B^+\to
\ell^+ \ell^- \ell^+\bar\nu_{\ell}}$ amplitude contains both the direct ($M_a$)
and the exchange ($M_b$) diagrams. We calculate a number of the differential
distirbutions. In particular, we propose an interesting observable that can be
readily measured experimentally - the differential distribution over the
invariant mass of the pair of leptons of the same charge, $\ell^+ \ell^+$. The
good news is that the interference between $M_a$ and $M_b$, $d{\cal B}_{ab}$,
is found to be at the level of less than 1\% in all considered differental
distributions and therefore can be neglected in the full kinematical region of
this decay.
