A quick visit to wikipedia(*) reveals that this song by Frank Loesser has been covered by many vocalists. Here’s a paragraph from that page, the last sentence of which is heavily ironic (since Lynn in fact did lose Frank to a younger prettier little thing, after introducing him to this new young lady) :
“During the 1940s, when Hollywood celebrities attended parties, they were expected to perform. In 1944, Frank Loesser wrote “Baby, It’s Cold Outside” for his wife, Lynn Garland, and himself to sing at a housewarming party in New York City at the Navarro Hotel. They sang the song to indicate to guests that it was time to leave. Loesser often introduced himself as the “evil of two Loessers” because of the role he played in the song.
Garland wrote that after the first performance, “We become instant parlor room stars. We got invited to all the best parties for years on the basis of ‘Baby.’ It was our ticket to caviar and truffles. Parties were built around our being the closing act.” In 1948, after years of performing the song, Loesser sold it to MGM for the 1949 romantic comedy Neptune’s Daughter. Garland was furious, and wrote, “I felt as betrayed as if I’d caught him in bed with another woman.”
*( I almost typed Wiki-leaks, darned modern media!)