In 1944, Loesser wrote "Baby, It's Cold Outside" to sing with his wife, Lynn Garland, at their housewarming party in New York City at the Navarro Hotel. They sang the song to indicate to guests that it was time to leave.
- Source: Loesser, Susan (1993). A Most Remarkable Fella : Frank Loesser and the guys and dolls in his life : a portrait by his daughter. Hal Leonard. p. 79.
It's always problematic to judge past events and behaviors by current social norms and mores. I am certainly aware of and sensitive to current issues involving sexual assault and harassment; but it is also important to understand that the lyric "What's in this drink?" could not possibly have had the same implications in the 1940s that it does since the '90s when rohypnol began to gain notoriety as a "date rape" drug.