Early versions of the term Irish Exit come from Irish Americans leaving social functions like Church, football games, and plays. When the functions let out people would congregate outside and chat with each person they knew and say goodbye before heading home. This usually added 30 minuets to an hour to the evening. Whenthere was little or no time to do the customarygoodbye, the family would leave through the side door. The side door move became known as the Irish Exit. The term has come to mean leaving a place withoutsayinggoodbye to those you are with or those you came with.
Joe-"Where is Timmy?"
Pat-"He pulled an Irish Exit about an hour ago!"