Fabulous new photos! That is a great top for "accidental" exposure. Would guess your wife would not have worn just that out and about but maybe by next summer she will...

I bought similar tops in different colors for my wife and it took a couple years before she would wear them as a single layer outside, first working in the garden and then to stores, etc.
Most women like to be found attractive and even better, sexy, by others so even though she protests as you found she really gets turned on at the thought of your friend seeing her. As Naakstel suggests, telling her your friend's very favorable reaction to her photos and what he gets to see when he is at your place may initially cause embarassment but inside you can bet she is molten hot. Keep up the good work - we are cheering for you!