Angellica, I realize that since you're not even a parent at this point that this probably doesn't mean much to you, but think about this anyway.
Let's say your teenager who kept their sexuality repressed for years -- well past the teenage years -- because of Mom & Dad's strict rules and harsh philosophy condemning homosexuality; that teenager grows up, gets married and starts a family, trying hard to live up to Mom & Dad's definition of "normal." At some point this teenager, now a parent with children, realizes that they can no longer live a lie and come out.
Now what are you going to do? Are you going to tell your child never to bring your grandkids around because Mom (or Dad) is gay? Will you punish them for something they didn't even do? How about your other (straight) kids never allowing your now out-of-the-closet gay kid's children to be around their cousins?
This thing is a bit bigger than your feeling icky about someone elses' sexuality. I hope you either NEVER have children or somehow come to your senses if you do. That scenario I outlined? That's my family. My kids, the ones who get straight A's in school and for whom I am constantly getting notes home about how respectful and pleasant they are to have in class -- those kids are left wondering why Grandpa doesn't want them around and why they aren't allowed to see cousin Claudie anymore.
Do you really want to be that kind of parent?