You can still easily do two cities/areas in your time frame if you can find direct flights to either https://en.wikipedia.org/wiki/Chania...tional_Airport or https://en.wikipedia.org/wiki/Herakl...tional_Airport of which there may be many depending on your actual dates. Connecting in Athens kills 2-3 hours over a direct. 2 days in Athens can be nice but I feel that visiting Crete you'll be slightly overkill on the Greek culture. I'd go with Budapest or Vienna if only for 2-3 days though one could easily spend a week in each.
Even Paris could be done with a nonstop from ORY to HER (not CHQ) but I'd suggest 1 more day in Paris anyways to get rest, adapt, get fat on Parisian pastries and all that good honeymoon stuff.