coupling in transmission line
Suppose I have 2 transmission lines. One carrying a high frequency
  sinusoidal signal. Is there coupling in a 2nd transmission line close
  to the 1st one


The problem you appear to have is that you are failing to recognize that all cables, wires and electrical connections are or can be regarded as transmission lines.

If you accepted this truth your question would become trivial i.e. "suppose there are two wires and one carries a signal, is there coupling from this wire to the next".

The answer always will be yes of course.