Erm, girls, please!!!
Wives know everything about their "man". They may pretend they don't, they may pretend they have not felt something going on. But ... they KNOW what's in the wardrobe, and pretty much everywhere else, cos tidying and clean-out is something "they" do. Of course you've never, ever looked in her knickers draw (and found an unexpected vibrator, and said "nothing" to her (*)), and likewise I'm sure she's never seen the inside of yours? Every item is in its place, they know where and how they left it. A stretched pair of her knickers tells her what you've been up to.
So, you can assume its a "DADT" situation, cos they're not comfortable with the conversation - it might be for many reasons. She might even be very relieved to know the truth. The thing is, it's better to know the truth, than to live suspicions.
That's in my world, and its worked. Maybe there are wives/SO's out there who don't look/know, maybe its a shock, maybe they'd rather think its an affair, but maybe they just need to know they are loved, first and foremost.
(* yes, its happened to me.)