Quoting Chim Richalds:" Does he say why he wants it cut? I'd corn row it to keep it out of his face and see if that feels better. ... [snip!] ... see if that feels better. I know long hair can just feel annoying especially before he gets tucking it behind his ears down."

He says he wants it like "dad's", but my husband head is shaved bald!  
What if he hates it?

corn row it. I couldn't cut his hair. lol
my son is only 6 weeks and I already told my dh I'm not cutting his hair lol

Quoting Mrs. Reynolds:" Yeh my sister is being a psycho about my nephew saying it's HIS decision to get it cut so until HE is ... [snip!] ... all around. He just needs it cut. Your boy looks like a boy, so that's no a problem, just irks me with my sister lol"

Does she not cut his finger or toe nails either?

I had a much milder opinion like your sisters, but at 3.5 the girl comments became too much. Although my DS was blissfully unaware, they were so frequent it was annoying and my son is increasingly aware so it wouldn't have been long before he noticed. My son's mixed race with dark hair and long lashes, i don't think he looks like a girl but i guess a lot of people where confused and didn't know boys can have long hair too   The only positive to people assuming your child is a girl is that they are kinder and most sensitive towards your child. Although very physical my ds is sensitive and emotionally perceptive so i think he'll find a difference in how he's treated if i shave it shorter when it gets hot.

At 2 i don't think it really matters as they're still babies, but over time it's not ideal. My ds is very firm if people call him a name and immediately corrects them, so no doubt as soon as he noticed people were calling him a girl he would've reacted to it. At 3 he knows he's a boy so it just didn't occur to him that people were actually talking about him when they said "she" and "the girl", but it wouldn't have been long.

Quoting S U Z I E:" He says he wants it like "dad's", but my husband head is shaved bald!   What if he hates it?"

Lol make your husband wear a wig. Tell him he's being a bad role model.

Quoting Mama*AtoZ:" Does she not cut his finger or toe nails either?"

That's what I said to her!! I also brought up the fact that she is FORCING him to be a vegetarian and I know he sure as smurf didn't tell her he wanted to do that. But she is kind of a terrible person and she doesn't care about anyone else but herself. I was hoping that would change with my nephew but it hasen't