I am not an engineer, but I’ve heard hardware stores will refuse to sell anything to you if you are trying to make a cord that’s male on both ends due to that being a crazy dangerous fire hazard
But still, plugs aren’t people anyway…
On that note “Oh but a key that opens any lock is more impressive than a lock that opens for any key.”
“Yes, but my vagina isn’t a lock, it’s a hole… and your penis isn’t a key, and it sure as hell isn’t unlocking me without my say so.”
They seem safe enough. I’ve never had one do anything crazy, so long as you respect it.
Assuming you plug it into the same receptacle or one that is on the same phase, nothing happens. Stupid for sure, don’t do that, but it’s already wired that way in the wall, you aren’t short circuiting anything with a cable like that (also assuming you didn’t mix up the neutral/hot wires when you made the cable). USA outlets at least. I don’t know about the rest of the world.