My wife is getting athletic! I am fantasising us being in relationship with another girl. Is this just a phase? Or am I losing my masculine side of thing?

Posting in this sub because I want the views of women who have faced this.. Or who understand the psychology behind couples relationship and their feelings..

Married. 5 years. AM, but I would say we love each other. I had a huge past. She didn’t and she is conservative too.

And she used to be a national player. She was very athletic. But recently she started going to gym and got bit more athletic. I am not that athletic. I have a sedentary lifestyle and spent my major time working. But I am skinny fat a bit.

Now she is in great shape and because of here height looks good amount of athletic too.

Recently one of her short friends came home. She used to comment about my wife (I know she was bi), like your boobs has gotten big etc. I don’t see her bad or anything. And we used to go to play game and all. Today after she left - my wife told me a dream she had that night. That I kissed her friend in cheek and her friend dismissed it as platonic. This was the dream. She told in another context. But this got me thinking.

And I am kind of fantasising about going to relationship with a girl as couple. Like us together with another girl. And I am confused whether that thought is a sign that I am losing my masculine energy or role in this relationship. Anyone went through anything like this?