I rarely even disagree with my mother-in-law, but there's one thing about which we are at an adamant impasse.
The word "pretty".
I have three sons, and I will tell you from here to Neptune that they are pretty. They are also handsome, attractive, gorgeous, etc., but my go-to description of them is still "pretty".
If she happens to be within earshot of me saying any of my sons is pretty, she chastises me. To be fair, usually she's polite and tactful about it (I am soooo rarely those things), but she does not let it go.
Neither do I. Why not? Because the argument for not calling a boy pretty is weak. Extremely so. Think about it.
A. "Pretty." by definition, is "giving pleasure or contentment to the mind or senses." By that definition, must "pretty" be exclusive to females? Nope. It's not even exclusive to animal, vegetable, mineral.
B. In the English language, nothing else designated as male is restricted from being called "pretty" excepting human/humanoids. A male horse can be pretty. A "male" car can be pretty. A "male" color can be pretty. Everything but a male human.
C. It's only fairly recently in human history that "pretty" became a term associated with feminine (or worse, emasculating) qualities.
Even if the definition of the word pretty were not so obviously gender-neutral, I'd still use it with my sons, and boys in general, because I think assigning gender roles to COMPLIMENTS is ridiculous. A compliment, by it's very nature, is uplifting and admiring. If I give one, it is that, a gift, and I mean it as such. It is praise. It is affection, and respect, and brownie points, and props (and really a lot more coming from me, as when I am not a shy or anxious person, I am a cynical, snide little thing, and rarely pay compliments).
It means you give me a sense of pleasure or contentment, just because I'm looking at you. Boy or girl, dammit, YOU. ARE. PRETTY.