Cold Squad (1998) : 6x10

Ali and Len re-open the case of a corrupt stockbroker, Jack Dolan, who had stolen millions from his clients. When they begin questioning the clients, they learn that Jack and his then-wife Arlene were members of a club of swingers. Originally they look at jealousy as a motive, but no one seems to have been angry about any of the relationships. Len also finds himself interested in the lifestyle of a swinger, which Wanda shoots down immediately. Nicco is finally finished his counselling sessions with Leanne, and when she calls him to her home he goes over and spends the night. The next day Leanne starts talking about their 'relationship', and when Nicco tells her she's moving too fast she accuses him of using her for a one-night stand.