That would certainly be a unique love token. I hadn't thought of that.
A cute reference to your son and his family...AK4. Concise and affectionate. Mine would be a little more complicated as I have three children. Our initials together are B, M, D, N, M. I suppose BNDM2 would work, though a bit awkward. We have nicknames for all of our children, so maybe we'll just leave it at that.

These are the kinds of counterstamps that really appeal to me. Pictorials are fun as often the meaning isn't obvious. Generally, you never find out, but the paths your imagination leads you down are interesting. I think I'll change the description of this one from "Flowers" to "Love Token?"
Bruce