I didnt enjoy with him..what should i do?

I had with this guy. It is the 4th time we are having . And after the 3rd time, i stopped enjoying with him but i decided to give him one more chance before i called it quits, ugg i had with him today, and i feel like i wasted my time. He doesnt even get me wet and this has never happened with any other guy that i have had with. He doesnt turn me on. I was thinking about someone else the whole time just to keep myself turned on until he s. WHat should i do. Btw, this is only a casual sex relationship.