He is married to Helen Theresa Tonay.
They got married on April 27, 1935 at Lehigh, Pennsylvania, USA, he was 22 years old.Source 3
Child(ren):
Baptism of Louis F. Demko - with Ciel Tonay and Joseph George Demko - Godparents
The baptism of Louis J. Demko. Father - Louis F. Demko, Godfather - Joseph G. Demko, Godmother - Ceil Tonay, sister - Helen Demko
http://trees.ancestry.com/pt/AMTCitationRedir.aspx?tid=113276500&pid=65/ Ancestry.com