Robinson, who also is a Baptist minister, said he thought he was having consensual sex with a young woman who had asked him for a ride.
Robinson says he handed her money to buy two sodas just before she performed oral sex on him.
Robinson said he was excited because he hadn't had sex in 17 years.
The woman testified yesterday she was a prostitute who was hired to lure Robinson to the motel.
The three men who are on trial deny the charges.