Butcher tells of sex with mother-in-law.
Julian St Quinton (33) is accused of blackmailing millionaire's daughter Samantha Stone, aged 26, to force her to drop demands for equal shares of their home when their four-year marriage ended.
St Quinton, of Blacksmith's Corner, Easington, East Yorkshire, spoke of a sexual encounter with his wife's mother, Linda.
'Sometimes I would go round by myself for a coffee. I was in the kitchen one day and she approached me.'
St Quinton said he and Samantha had taken part in group sex sessions with several other couples during their marriage.
The hearing continues.