What's the deal with those sonogram movies?

[dude8688]

You've probably seen them online, 'doctor' scenes where the sonogram shows the dick thrusting in the bottoms guts? Is it real? Or just a silly fad/trick? If real, what do you think of it? I find it hot to see the cock stabbing into the bottoms' insides, just wish the ejaculation was visible! 

[BootmanLA]

It's possibly real (I imagine a cock would show up on a sonogram in someone's ass, depending on the angle) but honestly, it seems kind of... overly clinical? ... to me.