1NT is alerted as 12-14.

You have agreed with a pickup partner to play DONT over a strong notrump and Cappelletti over a weak one, so your 2♦ shows the majors. However, when asked the meaning of your bid, partner says it shows diamonds and a higher suit.

What is the ethical bid in this situation?

Also, what is the (possibly not ethical) but most favorable bid you can make?