I will be honest, I do not get this whole thing about sitting down and outing your sexual history. I don't get it, the people mature enough to let past relationships stay in the past don't care about this stuff. Those who do usually end up using against their partner or themselves by making comparisons.

Anyway that wasn't your question.
When he is talking listen to where he puts the "I", "you", "us".
How much of what he says is, "i need/want"
How much is what can "we" do?
How much is what do "you "need..

This is a small window into your life, and you currently sound balanced and confident in what you feel you need for this to work.
Trust yourself, sit talk and explain,maybe if you can both really get how the other feels about it, it could work.

I say it again, TRUST your instincts.