S37·E178 Episode 5082 (Thu 4th Sep 2008)

Doug visits Brenda to apologise for coming on to her, but when Brenda goes to get them a coffee, Doug gets a nasty itch in his groin. Brenda returns to witness what appears to be Doug touching himself up and she is horrified. Doug tries to protest, but Brenda rings the police. Doug is taken into the station and when Ross spots him scratching, he sends him to see the doctor.