Hi Jessica
The only thing that I have found concerning his life outside of the Luftwaffe is that he was married in July 1942 by "Ferntrauung," a wartime policy by which a soldier be married by mailed documents, at Krasnogwardeisk in Russia. This information from
http://www.pilotenbunker.de/Jagdflie...tto-Kittel.htm which also includes a photograph of this event. Unfortunately there appears to be little more that I can help you with. Perhaps a German genealogical website might have some more answers? Take care and best of luck in your research.
Horrido!
Leo