Some part of the problem might have been a straightforward case of sexual incompatibility? Sounds like he cared about you, but realized you each had a different attitude towards sex.
No matter how much he liked/loved you, if it was clear to him that you were noticeably less adventurous in the bedroom than he was, (for whatever reason) then he probably was correct and wise in ending the relationship on those grounds. (Not saying either party was right or wrong in their attitude.. just incompatible with each other.)

As for the duality...'let's-have-kids/let's-break-up duality'... he probably thought you would make a wonderful mother... but still remained concerned about the sexual incompatiblitity

You mentioned your past as one reason for being concerned about his brand of sexual advances... so perhaps it would be useful for you to see a sex therapist ... to gain further understanding of your own sexuality, and how past experiences may have affected your perception of your exbfs suggestions.

It's good that you are examining the reasons for relationship breakdown,.... by understanding your own part in the problem, as well as the partner's part, it helps to break the pattern of mistakes and unwise choices. (BTDT)