Alright, screw it. You know what, anus-haters? It's time for a short rundown of the mouth of Hell that you're perfectly willing to stick your penises inside.
First let's cover something called "yeast infections". Yeast is a fungus that lives in the vagina. And this horrid thing can cause something called a yeast infection, and in fact yeast infections are very common. That vagina you're after has probably experienced this before. As per webmd:
Cottage cheese. They're not only baking bread in those things like some type of demented Crotch Pockets, they can also spew out cottage cheese-like substances.
What about periods? Oh, you should know about periods. Period days make lots of blood come out of the vagina - chunky blood. Uterine linings and clots mix in this like some type of vagina stew, all waiting for that time of the month to erupt forth like Hell's version of Old Faithful. These vagina blood geysers are something that 99.99% of women deal with monthly for a long span of years. Have fun.
Oh, and vaginal discharge. You see, vaginas clean themselves like cats, if cats were Predator-style penis-eaters. Only instead of licking themselves clean, they produce acids to do that. Yes, vaginas produce acids. And not just any acids - these acids can literally dissolve panties and various other things. Women can vary on this from being "dry", which also equates to a very dirty vagina, to being the fountain of eternal horrors. Vaginal discharge can range from clear and odorless to, let's see...
There's that term again: "cheesy". I don't recall when an anus last turned out to be a cottage cheese factory, but that's beside the point. That cheesy discharge is primarily due to yeast infections, which means that all-too-common yeast infections can cause double production speeds of this stuff.
I'm not even actually done, but I think that should cover it from now. This is your nirvana, straight men. But anuses are too much for you because "that's where poop comes from"? Anuses produce human waste, but so does your penis; vaginas produce humans, along with every other substance known to man. Since you've made the decision to use these to penetrate exclusively, you've entered into a nightmarish world of cottage cheese. Don't worry though, you won't be called "gay" for daring to consider the anus.