Apparently
these are John Barrowman's man parts.
Mm, cockring. The mantits and the jaw (see the dimple on the chin, even though it could be pastede on) are a good match, as is the way the guy is sitting. If it isn't Barrowman, it bloody well is someone who looks a LOT like him, a better match than whatever I could come up with in Potatochop.
So yeah... it's pretty fucking convincing to me at least.
ETA: Also, it could be a pic of John in his underwear with a cleverly pastede-on crotch? Difficult angle for that, but damn, that's a good job if it's a Photoshop.