For the past decade Betheul Moloto has played Russian roulette with his health.
He is HIV-negative while his partner is HIV-positive.
The unemployed couple live in an RDP house in the Matikweni section of Tembisa on Gauteng's East Rand.
But Moloto and Sonto Mabaso do not use contraception, even though his wife died of an Aids-related illness.
"We never use condoms," he said, looking at his 33-year-old partner.
He had never used condoms with his HIV-positive wife either, he said.
Moloto has been tested for HIV 12 times during the 10-year relationship. The tests have been negative every time.
The first time Moloto tested was in 2009 when Mabaso contracted tuberculosis and a private doctor insisted that she bring her partner along.
"That's how I learnt about Sonto's status," Moloto explains.
He was advised to use condoms but, after he continued to test negative, he stopped having protected sex.
The most recent test - in July - found he was still free of the HI virus.
The couple's situation - in which one partner is negative and the other positive - is medically known as sero-discordancy.
Studies have shown that circumcised men have between 60% and 70% greater protection against HIV.
However, Moloto has not been circumcised.
What bothers the pair most is the fact that there is no explanation for Moloto's negative status.
They have started assuming the virus simply does not show up in his blood.
According to both of them, Moloto is HIV-positive.
"This one is a ticking bomb, one day he is going to get so sick and will drop dead," Mabaso said.
Moloto - who still does not believe it is necessary to use condoms - is so distressed that he spends every cent he has on immune-boosting supplements as he believes the "virus" is secretly eroding his immune system.
"Physically, I am HIV-negative but psychologically, I am positive and this is the reason I see no use in having protected sex.
"How do you explain me continuously testing negative when my wife died of Aids and my current partner is HIV-positive?
"Though I have had unprotected sex with them both?
"To be honest, I am scared," he says.
Moloto has gone as far as asking his sister, a nurse at a public health facility, to arrange ARV treatment for him. She has refused.
Moloto also asked his sister to take his blood sample for a CD4 count. Again, she refused.
"I am not getting an answer from nurses at the local clinic.
"All of them say they do not know the explanation to my situation. I am physically HIV-negative but psychologically I am and this is killing me slowly."
Masombuka is an International Women's Media Foundation HIV/ Aids Investigative Journalism Fellow