Bob Morley has been cast as male nurse Aidan Foster in the soap, a love interest for Pappas.
The former Home and Away actor said that it made no difference whether or not his character was gay when he signed on to Neighbours.
He told the Herald Sun: "I don't see it as a big deal that the character is gay.
"It certainly doesn't define him and what the writers have planned is really interesting and authentic."
Morley's contract is currently for six months, but it may be extended in the future.
Neighbours' executive producer Susan Bower said that it was only a matter of time before Mason's character had a love interest.
She explained: "To be true to the Chris character, now he is a regular in storylines, we knew at some stage he needed to meet someone.
"How it unfolds, all will be revealed. However, I think viewers will find the story compelling."
> Read our Neighbours spoilers and news