What you are describing is not uncommon in couples that have been together for a while.
With time, the novelty of the relationship wears off and the honey moon stage can easily become one of boredom. When people get to know each other more and had been doing things for a while, they become too comfortable with each other and do not at times think to bring some spontaneity into their relationship.
It may be a good idea to talk with him and the two of you to come up with different things that you can do for fun. Variety keeps the world going.