The actress was brought in as advertising executive Don Draper's office assistant Megan in the fourth season of the period drama, and the two characters embarked on a love affair which resulted in marriage, bringing Pare back for the current season five.
But Pare insists she wasn't worried about being written out of the programme - she was content just watching Hamm and his leading co-stars from the sidelines.
She tells New York Magazine, "Every time I did an episode, I didn't know if I would be back. I was just happy to sit in the background if they did a scene in the reception area."
And when production on Mad Men was shut down last year (11) due to a contract dispute between the show's creator Matthew Weiner and bosses at TV network AMC, Pare was sure Megan would be killed off at the start of the new season.
She adds, "I kept saying, 'Two words: closed casket'. It (season premiere) opens on a closed casket. Pan up to Don, bereaved, winks at a blonde down the aisle. Bye-bye, Megan."
Instead, Pare stole the show when the programme returned to U.S. screens earlier this year (12) by performing a sexy rendition of Gillian Hills' 1960s French tune Zou Bisou Bisou in character at a birthday party for Draper.