Good question. I only have two platies. I thought I had a female and a male. Then the male had babies. I had only had the little trickster for about a week and honestly hadn't paid that much attention. She's a hifin and her dorsal fin is so long both the person who sold her to me and I thought she was a he. Now, it is quite obvious to me that he is a she. I guess she was all clamped up at the store. Now she's all happy and I can see her well enough. Anyway, the other platy has been in there for months and months by herself. I was hoping to get my red sword to make some interesting hybrids with her (she's blue), but he has shown no interest with a female sword in the tank. When I got her, I hoping she was too young to be pregnant because she was really small and skinny. Now she's all fat and looks perma pregnant too, For awhile I was all excited thinking the sword had been busier than I thought, but she has literally looked the same for at least two months. I have so many fry in that tank there is no way she could have given birth and had them ALL been eaten. I have guppies, swords, now platies, and even corycat fry that survive in that tank. There are so many babies and I feed so heavy that the adults just really don't make enough of an effort to clean out a whole brood. Oh, I just had a thought! Aren't there balloon belly platies? I wonder if our perma pregnant looking ladies have a touch of balloon in them. Hmm, that would certainly account for the chubbies in my fish. Yours has males though. She really SHOULD be pregnant. Always the possibility that she is infertile and just fat. You may have the world's only infertile platy. I had the world's only infertile molly. Had her for years and never had a brood to my knowledge. It happens.