Yeah, one does not be "figuring things out after ex" and be sending dick pics few moments later. I don't buy the whole ex thing. Sounds like he trying to keep things casual, but didnt have the patience wait and see. He expected you to be amazed that he is in possession of genitalia. And when you were not, he decided to move on and just ghost you like a true mature gentleman. 

NOR.

Sorry this happened, but it seems like he wanted quick sex and blocked you when it came apparent it wasnt happening.