It comes after the actor stripped off and bared all for steamy sex scenes in the new raunchy thriller.
WARNING: SOME PHOTOS CONTAIN NUDITY
But fans streaming the show got a shock when they goggled Richard and discovered that he is in fact 51-years-old.
Taking to Twitter, one said: “Moving away from (coughs) that particular part of Mr Armitage .
“Can we agree that Richard Armitage has a fine body for a man of his age and has nothing to worry about.
“He’s actually in better shape than some men half his age !
While this viewer tweeted: “I cant believe Richard Armitage is 51 and hot, and is not yet married.”
Another fan echoed: “Richard Armitage how come are you so hot and 51?”
Netflix’s Obsession sees Richard’s character William strip off to enjoy a series of steamy romps with his son’s girlfriend in the eye-popping series.
The actor was clearly not afraid of showing off as he went full-frontal for the erotic new series which follows the story of an illicit sex-fuelled affair between William and Anna, the fiancée of William’s son Jay.
In the BDSM filled show, Anna tells William that she is in control of all of their interactions when they are surrounded by family or out and about in public but tells him when it comes to being at the flat and in the bedroom, he can take the lead and do whatever he likes.
“Kneel, and I’ll give myself to you,” says Anna in one lustful scene.
Things take an even kinkier turn of events when she tells him to “hurt me,” before saying “thank you”.
The show is jam-packed with racy moments including one scene where William is left humping a pillow that smells of Anna’s scent after booking himself into the same hotel room she had stayed in the night before with his son, after becoming obsessed with her.
However, aside from Richard’s solo performance, William and Anna, played by Happy Valley star Charlie Murphy, end up unable to resist each other as they rip one another’s clothes off at every moment they can.
In another raunchy scene the pair are both on their knees, naked and embracing in front of a window.
The story of the affair is told across four episodes each packed to the brim with sexy scenes.
Richard shot to fame with his first leading role as John Thornton in the hit period drama North & South in 2004.
The actor then gained world wide fame when he played the dwarf king and leader Thorin Oakenshield in Peter Jackson’s film trilogy The Hobbit brought.
Obsession is available to stream on Netflix now.