“To me, sex is a very intimate experience of sharing your energy. Why was he so willing to share his?”

Exactly. You can’t know that you won’t be taken casually.

“My own trust issues came into play the minute he talked about a married woman.”

They aren’t your trust issues. He lacks the respect of relationships so much that he is willing to engage in something that will ruin someone else’s life.

“A high sex number doesn’t signify promiscuity, but it does say a bit about who you are.”

Well, it definitely often signifies it, perhaps not always conclusively determines it.

“Your number does not lower your value”

No, but it can lower your romantic value.

“Every time you give your body to someone else, they hold a piece of you forever.”

Hard to prove to people, but true.