I agree that you need to ask him why he does this. And for what it's worth, I think that it would be helpful to express anger and hurt about the fact that he does this to you. I know that you've asked him to stop - but you need to TELL him to stop - and in no uncertain terms. Do not use the word "please" when you're telling him to stop.
How often have you gotten out of bed and walked off, leaving him unfinished, when he does this? This guy needs some serious negative consequences for his behaviour.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.