Aunt Vanessa was driving her niece Tegan to the airport one morning when she got a flat tire. As Tegan ran off to get a new one (because she's a strong independent woman), Anthony Ainley turned up and asked her and a police officer to go down on him. They did.
Vanessa served as Tegan's version of Vicky when she wanted to explain her reason for leaving the TARDIS; "My Aunt Vanessa said, when I became an air stewardess... If you stop enjoying it, give it up. It's stopped being fun, Doctor. Goodbye..."