Mairead Philpott tells the court that she started having sex with other men before Christmas.
She says Mick was always present and that he would encourage it and agreed he would get involved.
On the night of the fire, Mairead says she had sex with fellow defendant Paul Mosely - something Mick would "encourage and join in" with.
This had taken place before the fire and Mairead said she felt "disgusted" afterwards, but that she did it to make Mick happy.
She says she was "really hurt" when Mick asked her for a divorce, but that she never thought about leaving.
More top news
There will be gales across Scotland and northern England this morning, but these will gradually ease through the afternoon.
An unnamed 14-year-old boy was taken into custody following the attack, Anderson County Coroner Greg Shore said.
Scientists hope to capture stunning images and valuable data in the final moments before its impact.