Sexualizing children

I have two little girls, but we have many friends who have sons. One thing I've noticed a lot is how they feel the need to sexualize their sons. For example: asking a mom friend what size pull up her kiddo wears because we have kids the same age and size... she goes on to say how they have to size up everything because of his large boy parts and how he just has more to fill a diaper. And then they just kept elaborating, even though I did not give a response. Mom friends are always saying how their boys are "well endowed like their father" and I just think it's gross and they are overcompensating for something while unnecessarily sexualizing their children. Like, why do they do that?