Grace Mugabe - who is 41 years younger than Zimbabwe's 86-year-old president - has spent the past five years cuckolding him with Gideon Gono, head of the country's central bank. But Mugabe learned about the affair in July when his sister Sabina revealed the scandal on her deathbed, it was reported, British newspaper the Daily Mail said.
The couple would meet as often as three times a month either at her dairy farm or in hotels in neighbouring South Africa. Gono, 50, is now said to fear for his safety. "Once he (Mugabe) hears something like that, I think someone will go to meet God," a Zimbabwean intelligence official was quoted as saying.
It is not the first time the first lady, who is known for her lavish tastes and expensive shopping sprees, has had secret affairs. One former lover, Peter Pamire, died in a mysterious car accident. Another, James Makamba, fled the country.
Gono has known Grace, who married the president in 1996, for at least 15 years and they are partners in a number of business enterprises. As one of Mugabe's most trusted friends, Gono has served since 2003 as head of the Reserve Bank of Zimbabwe - a period that saw the country's currency suffer hyperinflation of more than a billion percent a year.
While many of Zimbabwe's poor people struggle to find enough food to eat, Gono lives in a 47-bedroom mansion with swimming pool, gym and its own mini-theatre. Sunday a source close to the banker confirmed that he and the first lady were lovers and claimed they had planned a life together after Mugabe's death.
The senior official in Gono's office told South Africa's Sunday Times newspaper: "Mugabe trusted Gono. He even thought our boss was taking care of the first lady, keeping a protective eye on her so that she could not again be adulterous."
Mugabe's relationship with Grace, his former secretary, is itself founded on infidelity. Two of their three children were born when Mugabe was still married to his first wife, Sally, who died in 1992 battling a kidney disease.