Yeah, exactly what Ammokkx said. Pretty much everyone plays characters of different genders than themselves. There are also many, many people that like all kinds of gender pairings, I've seen no lack of other girls/fujoshi/fujin looking for MxM stories here. It's not so much you are "pretending to be" a male, but you are writing a male character. You aren't trying to dupe anyone into thinking you're male. Pretty different in my opinion.