You need to spice things up with him. Do something different, break out of the routine, use imagination and role play. Sex is a lot more than just two bodies touching each other, it has a lot of psychological and emotional parts as well. Find out what he's turn ons are and use them. If you don't things will become even worse. The idea of routine like, monotonous sex in itself will become repulsive and old very quickly.
Don't cry, don't regret and don't blame
Weak find the whip, willing find freedom
Towards the sun, carry your name
In warm hands you are given
Ask the wind for the way
Uncertainty's gone, your path will unravel
Accept all as it is and do not blame
God or the Devil
~Born to Live - Mavrik~