Yeah I know, not again

I have so much trouble with this female/male plakat thing! Somebody needs to make a sticky about this or something :p
Anyway, I went to the petstore near me that gets PKs in all the time, and doesn't realize it. Their new shipment had a lot of fish that I liked, but they're all really young. I can't tell if any are males... So I took some pictures

I really need to learn to identify them myself! I have room for one more boy, or a couple girls. I can't decide which right now...
Anyway, here are the pictures.
This one, acts totally male. Flares at every other fish in the adjacent tank. There are no other bettas in the tank with him/her.


This one (the white one) looks totally female to me, the shape of it's body, but the anal fin is kinda big, and it flares at the other bettas (the males.) I really like this one a lot



And this one, I don't know.... It was flaring just like a male, at the other one I thought was a male...

So what do you think? Do they all look like females? All of their ventral fins are pretty small/thin, but they are still very, very small bettas...