|Time on show||2002 Special episode|
|Relatives||Edina Monsoon - mother|
|Occupation||Scientist - geology or biology|
|Family||Marshall Turtle - Father|
Serge Turtle is Edina's only son, fathered by Marshall, Edina's first husband. Serge left home as a university student, and has never returned. He is much loved by Edina, and often used as an example to Saffy of what an ideal child should be in Edina's eyes. In the earlier series of the show, Serge is an unseen character whose whereabouts are referred to occasionally by Saffy, who is in contact with him. At one point, Serge does seem to return home, only for Edina to later realise it isn't her son, albeit only after she buys him a "sporty hatch-back" and gets him a job on the TV show 'The Word'. Edina is in direct contact with the real Serge at the time of Saffron's wedding, although (off screen) he tells his mother he is unable to make the ceremony, promising to be there for the reception. His bedroom is maintained at the house, although it is off-limits to his mother. She eventually breaks in but realizes she no longer even knows what her son looks like and is shocked when Saffy shows her a picture which she mistakes for Jimmy Osmond.
In the 2002 special "Gay", Serge, played by Josh Hamilton, makes his first and only appearance, when Edina and Patsy take a trip to New York, where Edina plans to track down her son, who, she learns from her mother and Saffy, is gay. On their arrival in New York, Eddy and Patsy track down Serge to a New York bookstore and at first mistake his partner, a flamboyantly gay American named Martin, for Serge. Eddy is disappointed at first to find her son is actually a more reserved and bookish young man. However, she embraces her son, who finally reveals that he left because of his mother's overbearing attitude and because she burnt his beloved books due to a claimed allergy to books (Patsy says they did it because they were cold). After some tension, Serge agrees to accompany his mother around New York. The episode ends with a flashback, showing that Eddy adopted Martin as her son in New York.