One of the things that's always been kind of fun about slash/yaoi stories is that they're pretty much porn/romance that's by women, for women. In that sense, slash/yaoi could in its own way be seen as an outlet for feminine sexual fantasies, but so could het or femmeslash written by a woman. Now, a lot of others would argue that het isn't a true exploration, because men are always dominant. If they're not on top, they have social norms that allows for their dominance [sighs and shakes her head]. And femmeslash? It's really about male voyerism anyway and all it does is keep women slaves to male fantasy.
The femmeslash argument I totally don't understand. One, if you write slash that makes you a flaming hypocrite and two, who cares who reads your fic? But the argument about het really confuses me, especially in yaoi when there's usually a designated "seme" and "uke." In fact, a lot of times this designation is encouraged, as it gives the woman someone to identify with but still lust after at the same time. Yet when those "uke" qualities are put onto a character with breasts and a vagina, its suddenly sexist and wrong and oppresses women.
What's so bad about being an uke, anyway? Hell, for the most part I'm one. I like to be pleasured by my partner, to feel like I'm giving myself up to someone who loves me and cares about me. It's what I like and it's what I feel my body likes. Sure, submitting can be seen as an act of defeat, of being overrun by somebody stronger than you. However, it can also be an act of selflessness, of getting pleasure out of seeing your partner in pleasure. (I've been enough on the other side of the D/s fence to know that much, anyway.)
People say this is fine in yaoi/slash as the two male characters would already have "equality." For one, this isn't always true. Take the two guys in my icon. They may be both guys, but there's clearly an age separation. Also, it certainly leaves female subs out in the cold. If she wants to submit, isn't submission taking control of her sexuality? Isn't being a top when she's not just giving in to a different sort of perception?
There are cruel, brutal men (and women) out there who are willing to take advantage of weaker people. But in the fantasy sex stories that are het/slash/femmeslash, THEY DON'T HAVE TO BE THERE. If you really feel like you need to hide your submissive urges in a male shell, I won't tell you not to. But if that's what you're doing, it's not feminist. It could be fun, it could be sexy, it could be an outlet for you that you really need, but it's not feminist. Writing a male submitting to another male will not change anyone's minds about whether females can be equal to males or whether females can do what they want in bed - it just won't.
And if you feel that you can't submit because submission is currently only acceptable in a male, then maybe you need to look at yourself for a bit.