I guess he hasn't pursued it because he totally believes that there is nothing wrong with it. Does he know that you think it's not right and that it could very well be a deal breaker for you?
I know one thing. If you do stick with him and have children... do not keep the baby in bed with the two of you, let him/her have his own crib and then bed and for goodness sake, make sure he is clear on the fact that he will not be sleeping with any of his children in their bed either. You need to break the cycle, not enable it to be perpetuated generation to generation.
If he's a good partner in every other way but for this unorthodox behaviour then perhaps you can encourage him to seek counceling. If he won't go then I'd end it. If he's never had counceling for the child sexual abuse then again, I'd end it. One cannot come to terms and be done with that sort of thing without the help of a professional to guide them through it. JMO.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion