Check out this link on voice sexing. If you have 2 males to 1 female that is a BIG problem. Drakes need 3+ females each. So you would need 6+ females for 2 males. I had 1 drake to 5 females and that wasn't enough and he tore up the backs of 3 of them.
if you Separate them from the female and she needs another female companion. Or You can add 6+ females for your two males or you can find one male a home and keep one male. Keep careful tabs on them and see if by chance it will work out but be prepared to separate them quickly if needed. Ducks can't be alone and you need more females.
Male ducks don't just stop after mating season and will mate all year long so you will need to do a permanent setup. Have 1 male to 1 female more than likely will not be enough so have a back up plan on what you will do if that doesn't work.
Could you get one female and keep the 2 females together and then keep the 2 males together. They would have to be separate flocks and never interact and see each other, but then you can keep all of them. How old are they now? I'm sorry to not have better news. The other option is to just keep the males and find the female a new home. The boys should be fine together as long as there are no females around. I had 2 males and they were great and happy together but they were the only ones. Ducks needs company and you can't just have a lone duck they get depressed.
