TMZ reports the Alaska native's girlfriend, Sunny Oglesby, gave birth to Johnston's second child Wednesday, a daughter named Breeze Beretta Johnston -- with the unusual middle name referencing the Italian firearm manufacturer. (Johnston, 22, is already a father to Tripp Palin, his three-year-old son with ex-fiancee Bristol).
In April, Johnston and Oglesby sat down for a chat with Inside Edition, during which he admitted the pregnancy was "unplanned."
"There was a time we went to the cabin and forgot the birth control pills, and a month later we found out we were having a baby," he explained of Sunny, a 20-year-old teacher who resides in his hometown of Wasilla, Alaska.
Johnston and his ex, the eldest child of former Alaska governor Sarah Palin, welcomed son Tripp in late 2008; the couple called off their engagement in March 2009, got engaged again in July 2010, but finally called it off for good just three months later.
"Bristol wanted to have a baby," Johnston sniped of Bristol, 21, to E! News in September 2011. "It all happened on purpose, and I was dumb enough just to roll with it."