I understand what you are saying about the double standard.
I am a guy and am not gay. But I do fantasize every once in a while what it would be like to touch or suck or be anally entered by another man.
But most men are hairy and ugly. Women are so beautiful and smooth and silky and wonderful.
So, I would be tempted to do a threesome with my wife and another man, as long as there was zero chance of other people finding out and he was curious like I am and straight and pleasant to look at.
Nothing against gay people. But that is not me and let me be me while I let you be you. I am just curious what things feel like.