I would guess that most lesbians are familiar with this scenario: you're talking to some random straight guy and somehow in the context of the conversation, you mention that you're gay.  The next thing out of his mouth is some variant of "Wait, so, are you bi?" and then when you say, "No I didn't stutter, I'm GAY" it's inevitably followed by "Damn. That's hot" or "Can I watch? Haha" and/or "Can I join?"  Makes me want to pull my fucking hair out.  

So why do men who are essentially strangers think it's totally fine to say such obnoxious and invasive things to you when you have just met them?  Per usual, I blame mainstream lesbian porn.  The scenes are always something along the vein of "experienced girl" teaching "curious, inexperienced girl" how to, you know, do it. But their version involves long nasty fingernails and exceedingly soft, non-arousing actions.  A writer at McSweeney's described the issue perfectly: "these spray-tanned young women lap at each other's nether regions like the world's most refined kittens at an eye dropper of milk." Well said, Lynsey G, well said.  

(this is not accurate, guys)

Anyway.  The point is that even this bizarre hardly-doing-anything girl/girl "sex" is what guys think that lesbians do constantly.  And for some even more bizarre reason (cough: porn), the straight dudes appear to actually think that we would respond to their inquiries to watch or participate with, "Oh yeah totally let me just go get my girlfriend and some light panels and I'll be right back to put on a show for you.  You can totes join after we warm each other up."  

Granted, the guys are right about one thing: lesbians DO have mind-blowing, incredible sex.  And they should be jealous, because our sex is fucking amazing.  But that's not what you see in porn.  And it's certainly not all there is to a lesbian relationship, idiots!  

My ex and I used to joke in certain scenarios--such as me putting her to bed after she threw up, or her telling me I had crazy garlic breath--"Wouldn't it be funny if a guy could see this and realize that lesbian relationships aren't some 24/7 pillow-fight-clit-festival?" 

Luckily, a brilliant writer over at McSweeney's pokes fun at this exact idea with a hilarious column that describes three "girl on girl" scenes in graphic detail.  I'm not going to spoil them for  you, you just need to read this and crack up.  For fun, I've written one of my own:  

Imagine it for a second:  A sexy brunette walks into the room, and stares at a blonde who is laying on the bed.  She slowly removes her shirt, saying, "Baby I have something to show you."  The blonde sits up in anticipation as the brunette turns around to reveal a patchwork of bug bites all over her back.  "Baby, could you get the cortisone and rub it on me?" she whispers throatily.  "Holy shit, those are insane" the blonde exclaims with a glimmer in her eye.  She grabs the tube of ointment and slowly rubs it all over the brunette's skin, pausing occasionally to say softly, "Oh..my god."