  Given a finite dimensional algebra A of finite global dimension, we consider
the trivial extension of A by the A-A-bimodule $\oplus_{i\ge 2}
\Ext^2_A(DA,A)$, which we call the higher relation bimodule. We first give a
recipe allowing to construct the quiver of this trivial extension in case A is
a string algebra and then apply it to prove that, if A is gentle, then the
tensor algebra of the higher relation bimodule is gentle.
