Not exposing your children to gay men and women? Okay, how about not exposing them to ... (select your favorite group you don't care for). I feel sorry for your kid(s)! They need every ounce of education, experience, and advice you can instill in them. Kids don't become gay because they encounter gay people and see them interacting: people are generally either born gay or not, as has already been pointed out. If you say you don't want to expose your child to gay people, that really means you don't want your child to see that as a lifestyle choice, because you're afraid your kid might turn out to be gay. It isn't going to happen, so get over it.
Having grown up in New York City, I don't know why someone felt it necessary to apologize for taking their 12 year old son to Greenwich Village. You don't think they're doing nasty things in the streets, do you? Please. Kids get experience and diversity growing up in Manhattan.
Now, I will tell you that I made it a point to stay inside most of St. Patrick's day when I lived in Manhattan because of all the drunken Irish folks drinking, peeing, and vomiting in the streets. Not a joke, just an observation. Anyone who has lived there has seen the same thing. Same as Halloween: watch out for eggs if you're walking around in Manhattan on Halloween--they have a habit of dropping out of the sky or getting tossed at you from moving cars.
Since I don't think gay people are tossing eggs, or drinking, peeing, and vomiting on Main Street, I wouldn't worry about going to Gay Day this year.