Am I about to make a terrible mistake?

[Person]

I have a few friends who are huge fans of the new My Little Pony tv show. We are all a little old to be enjoying it so much (18 to 19 years old), but we can't help it, we love the show to death.

My friends post funny captioned pictures with the pony characters in them on Facebook. Some of those pictures are downright hilarious, and I've been tempted to share the pictures on my wall too. I asked my sister if that would be fine, and she said: "I have 3 big reasons why that is absolutely NOT fine:
1. You will not taken seriously by your friends, family, co-workers, or prospective employers anymore
2. You'll annoy the hell out of all of the people on your friends list
3. You won't have a chance of getting a girlfriend ever again"

I just want to post a few of them and share my interest, but my sister says that there could be major repercussions if I do that. I don't want to set-up a fake account to post my pictures from. What would be the point of that if none of my friends were seeing them? Plus, I think it's wrong to judge a person by the type of humor or media they enjoy, so it'd be their problem, right?
What do you think I should do? Would you be annoyed by funny pony pictures?