  We consider global 2-SLE$_{\kappa}$ $(\eta_1, \eta_2)$ in a topological
rectangle with $\kappa\in (4,8)$. We derive the law of a random hitting point
of the curves and show that, conditional on this random hitting point, the pair
of two curves has the same law as Gaussian free field flow lines with proper
boundary data. Using a similar idea, we derive the asymptotic of the
probability for $\eta_1\cap\eta_2=\emptyset$. As an application, we derive the
asymptotic of the probability for the existence of two disjoint open paths in
critical FK-Ising model.
