When it comes to sex, my general philosophy is, if it's isn't hurting anyone and both parties are consenting, then what people do is their own business.
That pretty much goes double for someone's fantasy life. Sexual fantasies are a normal way to explore sexual feelings.
Still, just because it is perfectly healthy to have sexual fantasies, that doesn't mean that once someone fantasies become public (say through a conversation, porn, or cultural references)that everyone is going to be comfortable with them. For example, even though fantasies are safe and healthy, the straight male "lesbian" sex fantasy can be uncomfortable for a lot of girls.
Here are a few reasons why:
- A lot of girls don't like being though of only in a sexual way.
- Girls (who may or may not identify as lesbian or bisexual) may feel like they should hook-up with each other because the guys around them think it's hot to see two girls make out, not because they really want to.
- Lesbian teens often feel uncomfortable about being turned into a sex symbol by people they have no interest in sexually. This can make them feel bad about their bodies. It can also make them even more uncomfortable showing any signs of affection with another girl in public.
Are lesbian sex fantasies the end of the world? Are straight girl hook-ups? Of course not. In fact, some might argue that the cultural acceptance of same sex female sexuality can be seen as a step towards greater GLBT acceptance. And though I would hesitate to buy that argument until gay male fantasies are seen in the same way, I also don't ever want to tell people that there is something wrong with their turn-ons. At the same time, it's important to realize the impact these fantasies can have on girls, both lesbian and hetero.

