The Republican governor's comparison occurred on "Ask The Governor," on WHP-TV, Harrisburg, in the state capital. He said in a statement that he was simply citing examples of types of marriage that are illegal under Pennsylvania law.
"My words were not intended to offend anyone. If they did, I apologize," Corbett said. "I explained that current Pennsylvania statute delineates categories of individuals unable to obtain a marriage license. As an example, I cited siblings as one such category, which is clearly defined in state law."
The issue is an explosive one at the moment in Pennsylvania. The state's ban on gay marriage is being challenged in federal court -- which Corbett said is the appropriate venue -- and Montgomery County in the Philadelphia suburbs is appealing a court order to stop issuing marriage licenses to same-sex couples.
In August, state lawyers in a brief in the Montgomery County case compared gay marriage to marriage between children. Corbett at the time called the wording "inappropriate."
Pennsylvania is now the only state in the northeast that does not grant recognition to same-sex relationships. Neighboring New Jersey still bans gay marriage but allows civil unions.
Notable deaths of 2014 [PHOTOS]
One Calif. deputy killed, three others shot