Humans have a contrasting mentality than any other living being. They get excited seeing different body parts such as boobs. If you ask any straight man, he will say that they love that jiggling and juggling body part of a female.
And this is not limited to only men, women too like to stare at other women’s package because of their own insecurities of not having the perfect boobs like the one they saw. Check out this collection of men and women caught staring at a pair of boobs.