I'd not address it directly. I'd say something like "I have nothing to hide." My W was similar with comments though they weren't accusatory. I always told her that she was more than welcome to see any of my electronic devices (full transparency) something she wasn't willing to reciprocate. Not sure if the experts here will agree with that approach, but likely she is curious as to if you have moved on to someone else and is gauging whether that is true or not.
Saying "I have nothing to hide" tells her what you were wanting to convey without directly addressing her accusation. If she really cares she will follow up with additional questions, and you'll have to be careful not to just show all your cards.
Remember, her being concerned about this is a positive for you. It keeps her curious, engaged, and interested in what you are doing.
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018
