Liam Stephen Hatcher, 25, is said to have met his victim, who cannot be identified, on dating site Fab Guys.
And on 9th October, Hatcher went to the victim’s house in Vale of Glamorgan, where the two had sex, before he drove Hatcher back to Cardiff, the court heard.
Hatcher’s mood was then said to “change completely”, suddenly accusing his date of raping him and saying if he didn’t hand over £6,000, he would tell the police.
Hatcher is also said to have threatened to post photographs of his victim.
The 25-year-old then drove the man’s car to various cash points, threatening him with violence and forcing him to withdraw money.
Eventually, Hatcher drove back to the victim’s house, where he stole various items, including gold rings and an iPad.
Hatcher left with around £1,400 and the stolen goods from the victim’s home.
Detective Sergeant James Dowler said: “This was a particularly vicious crime and I hope today’s sentence offers some closure to the victim who has demonstrated immense courage throughout this investigation.
“Liam Hatcher targeted his victim using a gay dating website and preyed on the fact that he is not openly gay.
“The victim not only feared being outed by the defendant, but also being falsely accused of rape by a man he had met for consensual sexual relations.
“While the majority of people using dating websites do so for genuine purposes, it is vital that people are aware that not everyone they meet online is who they say they are.
“Some people use fake identities to lure people while others, as in this case, reveal their true personality once they have their victim firmly within their grasp.
“Our main advice to the public is to use these sites with caution, but should they find themselves a victim of crime, whether it is sexual assault, blackmail or sextortion, or other, it is vital that they report it to the police.
“I can assure them their report will be taken seriously and treated with the upmost sensitivity and confidentiality.”
Hatcher pleaded guilty to blackmail in an earlier court hearing, and has now been charged with five years in prison.