Of course that would've meant a topless Angelique, and a lot of bed-hopping for Carolyn...
Oh, yes, the "varied" possibilities are seemingly endless: Carolyn and Phillip Todd, Mrs. Johnson and Ezra Braithwaite, Donna Friedlander and the Eagle Hill Cemetery caretker, Prof. Stokes and Madame Findley, Buzz Hackett and Leona Eltridge, Jeff Clark and Portia Fitzsimmons, Sam Evans and Eve, Judge Crathorne and Megan Todd, etc., etc.
You forgot Willie and Barnabas ala 'Queer As Folk'. Hey, the ABC censors thought it was implied....
Evidently, by 1969, ABC's "sensitivities" had mellowed considerably, since we got to see plenty of "same-sex" neck/throat biting from Barnabas.
There were same sex neck bites in later storylines, BUT the actual act was never depicted as it was with male on female or female on male.