This isn't about gender, it's about sexual orientation.
So, after I answer this, I'll be mopving it to GLBT relationships.
Having any sort of sex for someone else's sexual entertainment is generally a bad idea. Plenty of people find thae fantasy of multiple partners "hot," however the fantasy of such and the REALITY of such tend to differ greatly.
For instance, yes, your STI risks are amplified when you take on more than one partner. Therefore, everyone involved would need to be practicing safer sex: meaning, condoms for any men involved, as well as dental dams and gloves for everyone. That doesn't figure into most people's threesome fantasies.
Same goes for high levels of communication and negotiation that multiple partnership tends to require to behealthy and not leave anyone feeling cruddy. Jealousy is also very common. To boot, having sex with friends can create issues in friendships, long-term, to grapple with.
You good yet at excellent sexual communication with existing partners? As in, expert-good? You good yet at getting to a sexual health clinic every year for your STI screens/ how about the people who want to be involved with this? I'm betting none of you have started doing that yet.
In other words, what seems light and amusing to your male friends is a WHOLE lot more complicated than what they see in porn.