Hi there, I too am dealing with similar issues, i.e. money being deducted from our checking account and the cell phone bill.
In the midst of my H's A I found out that he had a prepaid cell phone. He apparently got this after I confronted him about his calls with OW on his regular cell phone. Now supposedly the A is over, (even though there was one very long call to OW last month on our bill) but I am worried that the money he is withdrawing is to pay for his prepaid phone card. I know, I could be a little paranoid.
In any case, I want to question him about the withdrawls but I don't want to be controlling. If it is for the phone card, then of course, he will lie. If it is harmless, then he will get defensive and say I am acting like his mother checking on every little thing he does.