Glen Marwood, 49, pictured above, using the bogus name 'Ricky' told the 17-year-old by email he was living in Michigan in the USA.
Leeds Crown Court heard the teenage girl fell for his sob story after 'Ricky' told her he was suffering from terminal cancer and went to live in America for treatment funded by selling his family's home.
Michael Collins, prosecuting, said 'Ricky' even posted a false photograph on his website claiming he was a Swedish male model called Robert Sinclair.
Their relationship developed, said Mr Collins, because the girl believed she was helping him to cope with his cancer and treatment of the disease.
Mr Collins said she began to see their contact as "romantic" and described it as a "whirlwind relationship" and they made plans for the future.
Marwood, under his persona of 'Ricky,' even persuaded her to use the webcam to see her picture but never reciprocated, claiming he did not want her to see him because of his loss of hair through treatment for his alleged cancer.
Mr Collins told how Marwood had gone on to talk about sex and how he had sex with a school teacher.
He said the girl was so supportive and convinced by his act she became emotional and weepy because she believed he was going to die - and even planned to fly out to see him in the States.
But, said Mr Collins, callous Marwood informed her 'Ricky' was dead which left her "sick and devastated" adding: "She cried for two weeks on hearing that news."
The girl's family realised they had been duped soon after Marwood went to visit the girl's family in the South of England bringing gifts on behalf of 'Ricky.'
Police investigated, said Mr Collins, and Marwood admitted pretending to be 'Ricky' and spinning lies about cancer.
"He said he went on the internet to escape from an unhappy marriage and describing what he wanted to do sexually to the girl," he said.
Marwood, of Chidswell Lane, Shaw Cross, Dewsbury, was jailed after admitting charges of inciting a child to engage in sexual activity and assault. His name will also be placed on the sex offenders' register for 10 years.
Jonathan Rose, for Marwood, told the court he apologised for the undoubted distress he had caused, saying his client's wife had been greatly troubled over many years with a depressive mental illness.
"She would spend long hours watching TV," he said, adding: "There was little or no conversation and there was nothing between them at all."
Passing sentence, Judge Ian Dobkin told him: "What you did was an extraordinary piece of bizarre behaviour - and it was very harmful behaviour."
He added: "She has made a statement saying she cannot trust anybody - and that is not surprising from what you did to her."