tl;dr: you don't owe him anything, AND if you were to split now, you'd be 50-50. This is because these initial commits are negligible wrt the 5-10 years you'll need before calling it success.
I think you should have a serious conversation with him on his intents and commitments for the future. If you're serious and want to approach investors, you have to be in a good position to explain both who's working, and who's owning the pie.
tl;dr: you don't owe him anything, AND if you were to split now, you'd be 50-50. This is because these initial commits are negligible wrt the 5-10 years you'll need before calling it success.
I think you should have a serious conversation with him on his intents and commitments for the future. If you're serious and want to approach investors, you have to be in a good position to explain both who's working, and who's owning the pie.