Girls are often encouraged to be athletic, assertive or like “tomboys,” while boys face no socially acceptable equivalent in the other direction. There is no benign male version of tomboy. The closest is “sissy,” not typically considered a compliment.
https://theconversation.com/gender-conformity-starts-young-and-boys-and-girls-fall-in-line-in-different-ways-275996
Gender conformity starts young – and boys and girls fall in line in different ways

Children learn what it means to be a woman or a man early on. How they respond to threats to how well they conform to gender stereotypes changes with age.

The Conversation
@amydiehl I'm curious where words like "nerdy" and "geeky" might fit in here. I can't think of any neutral or positive synonym for "sissy", which is a particularly negative one, I think. "sensitive" is at little more neutral, but not without baggage.