Schnübling
What you call dating when you know you are dating but your parents prefer to not use the word "dating". 'Schnübler' is the word used in place of boyfriend or girlfriend, or dater.
"Well, we're not dating, but we're definitely schnübling."
"This is my Schnübler, Peter." We are schnübling together."
"This is my Schnübler, Peter." We are schnübling together."