Can anyone tell what sex they are?

Ok I finally got a couple pictures of Abbott and Costello. I'm not sure if they are good enough for someone to tell what they are. But I think my little boys are little girls. Guess they don't really care what their name is though.lol.
If these are not good enough please give suggestions on how to get better pictures. I was afraid I would hurt them...

Thanks
Alexa

the 1st pic im not too sure about but the 2nd pic definately looks like a girl

The first picture is of Costello...the bigger of the two and the one that seems to be getting a bit aggressive...right now he just head butts and Abbott just waves. But the majority of the time they still get along. I watch them all the time and keep them seperate when i'm not there just to be sure.

how old are they?be very careful,you dont want an accidental mating if they are m/f from what you said,i assume they are caged seperately right?

what do you mean by "head butts?" If he is bobbing his head and she is waving, most likely you have a pair....

Just because one bobs its head does not instantly make it a male. Based on the pics I would guess both female right now, but based by age, you still can't be sure. There are such things as aggressive females. But even still one will establish dominance over the other regardless of gender. And the other will submit. I even have a group of females, and yes I am certain they are, who go around and mock breed one another. There are just certain hierarchies that must be established in any group. And even tho one looks and acts normal, does not mean the stress from being subordinate is not affecting them. Or vice versa. Hormones are doing crazy things now and if it were me seeing these behaviors, I would separate them. Even for the fact that alone each one would have a better growth rate without the added stress of competition. Even if they have their own furnishings and bowls there is still competition, glances, and just general presence of another that will stress them out. But that is just my opinion and experience.

They don't bob their heads....Costello just kind of runs at Abbott and butts him with his head. They are now close to 8 months old. I do separate them when I can't be around to watch them...but when I'm there they are together most the time. And most the time get along. I really think they are both female the seem to look the same on the underside. I only have a 20 gal. tank at the moment to put the other in and hate to keep one in there all the time. I'll Get a much bigger one like the one they are in at the next reptile show. But I don't leave them together when I'm not home or not around. They are in the same room with me and I have an in home office so I keep a very close eye on them and I defiantly don't want breeding.They are litter mates and I don't want babies...heaven knows there are enough what I call backyard breeders out there.
Thanks so much for everyones help.