Sasha is a boy. For example: both he and Sabrina have one older brother. Sabrina, from time immemorial, has loved pink, princesses, baby dolls, and so on. Sasha makes guns and shoots badguys. He will brandish a stick/tinkertoy/finger at me and say, "I a SUPERHEWO. Kill da badguys. Pchooo pchooo." Sabrina does not make guns sounds.
Sasha is also physical. His default setting is "run," he was kicking a soccer ball before he could really walk, and he pushes his sister for fun. We bought a toy excavator at Costco that Santa will give him, and he held it all the way home. Twactow! he says, as we drive by a construction site.
So his answer when asked what he wanted for Christmas surprised me. "Pwincess bike," he said decisively. Zane was not amused. "How about a Diego bike?" Zane riposted. Frankly, Sasha's favorite show is Dora, so how about that?
On second thought, though, maybe I shouldn't be surprised. The first color Sasha learned was pink, and he always wants his fingernails and toenails painted. Having an older sister certainly has influenced him! Based on his other attributes, though, I'm convinced Sasha is simply secure in his masculinity and thinks painted fingernails looks tough.