In 1765, aged 8, he inherited the estate and manor house of
Knighton Gorges from his grandfather Lieutenant-General Maurice Bocland. He became a captain in the South Hampshire
Militia, which covered the Isle of Wight. Bisset became a close friend of Sir Richard Worsley, his near neighbour on the Isle of Wight. As was revealed in the court case, with the encouragement of her husband, Bisset began an affair with Lady Worsley and in August 1781 she gave birth to his daughter, christened as Jane Seymour Worsley, whose paternity was nevertheless accepted by the baronet, to avoid scandal. In November 1781 Bisset ran away with her so she could escape her failing marriage with Sir Richard. They were however discovered and in February 1782 Worsley brought a
criminal conversation legal action against Bisset seeking damages of £20,000 (2023: £). Seymour, who was rumoured to have 27 lovers, turned the case against Sir Richard and made it clear that he had consented to and even encouraged the relationship between her and Bisset. This testimony destroyed Worsley's suit and the jury awarded him
nominal damages of just one
shilling (2023: £). ==Marriage and issue==