Most of the time, you don't even need to see their genitals.
Look at it another way: Of course you need to see their genitals, but there are plenty of other indicators that can usually stand in as a reliable proxy for those genitals. A straight dude sees another dude, he doesn't need to see the johnson itself. He already knows he's looking at a dude.
The problem only occurs when a dude passes so successfully as a lady that the other dude doesn't realize he's looking at a dude. Then he's understandably upset when the scenario goes all Crying Game on him.
And apparently now there's a second problem that comes up when a dude doesn't pass as a lady, but still wants other straight dudes to pretend he's lady, and feel heterosexual attraction to his johnson.
Honestly, PT, the best explanation for your posts in this thread is that they're an anti-trans false flag.