A man is about to die

His end is near, his wife is by his bed, holding his hand. No doctor was able to find out what exactly made the man so sick.
Suddenly, the man starts to cry. He sobs:
"Darling, I have to tell you something before I die."
She holds his hand even tighter and says:
"Shh, stay calm. You don't have to do anything!"
But he insists:
"Darling, I made mistakes. I slept with your best friend."
She stays calm:
"It's ok, don't worry about that."
He continues:
"I also slept with your sister."
His wife still remains calm, again she says:
"Honey, it's ok. Don't worry about that."
He tears up once more and confesses:
"I... also slept with your mom..."
His wife smiles at him, says:
"Honey, I know all of that. Now calm down and let that poison finish its job."