What's to be confused about? Jose showed you who he truly was. Someone who lies to get what they want. So now that he has shown you who he really is, believe him. He hasn't changed - otherwise he would not have lied to Ben.
If you want to preserve a 'hi, how are you?' kind of thing when you run into each other, I don't see why not. But I need to trust my friends as well as my lovers.
There are plenty of poly fish in the sea. You will meet others interested in you, and willing to be open and honest themselves.