If you are prepared for the heavy tan and heavy humidity than go for it, if not visit in winter's, place remain same but in winter you will thank the weather.
I recommend to go in winter as it is sorrounded by complete water...the humidity is very high....so in that case winter is the best season to visit Andaman
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.
Sea is good 365 days. However be ready for tanning. Make sure you stay at Havelock and Neil island. As rest areas are too crowded. Spend more time at these two places.