While Andaman Islands are picturesque throughout the year, the humidity in May would restrict you from exploring the places to the fullest. Since it is literally in the middle of water, the heat and humidity can be too much to bear.
You can consider some other destinations like Himachal Pradesh or North Eastern places to go on your honeymoon in May. If you insist on Andamans, my suggestion would be to wait out the summers and visit the islands somewhere around October-November. The crowd of tourists gradually increases in December.
Hope that helps.
Congratulations on your wedding! Have a fantastic honeymoon.