  In mechanically driven superfluid turbulence the mean velocities of the
normal- and superfluid components are known to coincide: $\mathbf U_{\text{n}}
=\mathbf U_{\text{s}}$. Numerous laboratory, numerical and analytical studies
showed that under these conditions the mutual friction between the normal- and
superfluid velocity components couples also their fluctuations: $\mathbf
u'_{\text{n}}(\mathbf r,t) \approx \mathbf u'_{\text{s}}(\mathbf r,t)$ almost
at all scales. In this paper we show that this is not the case in thermally
driven superfluid turbulence; here the counterflow velocity $\mathbf
U_{\text{ns}}\equiv \mathbf U_{\text{n}} -\mathbf U_{\text{s}}\ne 0$. We
suggest a simple analytic model for the cross correlation function
$\left\langle \mathbf u'_{\text{n}}(\mathbf r,t) \cdot \mathbf
u'_{\text{s}}(\mathbf r',t)\right \rangle$ and its dependence on
$U_{\text{ns}}$. We demonstrate that $\mathbf u'_{\text{n}}(\mathbf r,t)$ and $
\mathbf u'_{\text{s}}(\mathbf r,t)$ are decoupled almost in the entire range of
separations $|\mathbf r-\mathbf r'|$ between the energy containing scale and
intervortex distance.
