A friend stumped me with this question: What is the earliest reference to the custom of having newlyweds dip their hallah in honey? My guess is that it's an extension from the custom of honey on Rosh haShana... Any ideas?
I checked through the Nitei Gavriel on Nisuin and there is no mention of such a Minhag. I personally have also never heard or seen such a custom.
The closest I found is the Rokeach 353 who mentions that after the Brachos of the Chuppa they give the Chassan and Kallah honey and cheese to eat based on the verse (Shir Hashirim 4:11) "Devash Vchalav Tachas Lshonaich" דבש וחלב תחת לשונך