Mmmm, nice pussy is the correct response.
If that were true, you’d take the advice in this thread instead of claiming you’re just being honest and helpful.
Read this. When you get to the last bit I quoted go back to the previous bit in bold. Think.
who doesn’t want to sleep with her again,
Actually, her vagina is fine, your dick is too small.
You’re welcome.
I once had a longtime online friend who subscribed to what he called “brutal honesty” in all his dealings, both online and off. I have no idea if he was THAT honest as the OP describes, but my friend’s reasoning was that telling the truth would keep himself honest in all his dealings and that “people MUST hear the truth about themselves no matter how much it hurts.”
Needless to say, he was very unpopular unless somebody felt like trolling him, which did happen with alarming frequency. Some of us thought it was just an attention-getting ploy.
I don’t think you should hide your real you. If your real you is so honest and brutal, by all means let it show from the first date! It will save you the time to spend with a woman that will later be turned off by your talk, and spare her having to hear your rude comments at a moment when people are usually their most vulnerable. It may decrease your rate of multiple dates and/or beddings, but it should be a good fair exchange, right? 
Not even the jerkiest guy I’ve been with (related to his work stress) was rude after sex. In fact, he was at his most pleasant and nice state, nothing negative at all. That you choose rudeness speaks more about you, and you only, that about some difference between men and women or about the women you’re sleeping with at the time.
This is important: DO NOT SLEEP WITH PEOPLE.
If you think being tactful and not blurting your every last thought is of paramount importance, why wait until after sex? Why not have every conversation like that?
“Hi, I’m Marjorie! Nice to meet you!”
“Hi, Marjorie, I’m Stringbean. Marjorie is a hell of a name.”
“Thanks, it was my grandmother’s.”
“Yeah, that’s what I mean. It’s an old-lady name. Say, you know your nose is huge and your eyes are on the small side. You’re a little chunky for me.”
[Marjorie leaving]
“What? You don’t want to labour under the delusion that those are good things, do you? I’m just being honest! You deserve to know the truth!”
Seriously. If this “brutal honesty” thing is so important to you, why are you saving it until after sex? I feel if you’re brutally honest all the time, the issue of women leaving you after sex will go away.
apollonia, that’s a not untypical exchange in the experience of online dating.
I know this is a worthwhile pile-on, and I hope we each receive a little trophy with an ormolu piñata-basher, but this isn’t too removed from standard treatment between significant others.
We bite our tongues all day because we want to look cool and magnanimous to the world, so when a cab driver goes blocks astray we won’t say anything about his incompetence or how he’s cheating us. But if our SO leaves a glop of toothpaste spit in the sink, they are dead meat.
It’s as if when we give our hearts, we lose (and loose) our sphincters as well.
Your after sex conversation should be something like “Wow… that was great… you are amazing… wow… you are gorgeous” and based on the level of the relationship throw in several " I love you so much."
But after reading your posts I think either “Thank you, Thank you, Thank you” and/or “your money is on the nightstand.” would be fine.
You are a liar.
If you were such an honesty junkie, you’d tell them about their weaknesses with your brutal truthfulness before you fucked them.
Your method of operation is not that of someone telling the world the tough truths about itself, it’s that of a coward who wants to be abusive, but doesn’t have the balls to do it except when the other person is at their most off-guard and vulnerable.
When’s the last time you went into a biker bar to correct the biker’s misguided apprehensions of themselves? “Hey, you big fat greasy slobs. You think the leather and unwashed hair makes you look tough? It really doesn’t. You look like an overgrown 8 year old who saw Mad Max and thought it was a valid lifestyle choice”? Or when was the last time you went to your boss and told him/her the complete truth “You’re a mid-level manager who’s job is apparently to get between me and my ability to be productive. You have no function except to create problems you then “solve” so you can justify your bullshit existence. Also, you smell bad, and when I saw you at the urinal, you have a tiny dick.”
You haven’t? Then you’re not a brave, noble truth-teller, you’re just an abusive coward.
I don’t have the cleverness of a lot of people posting in this thread, but I would add one observation: Perhaps your “brutal honesty” after sex is simply a way of creating emotional distance between you and the person you slept with, because having sex has moved you too emotionally close to that person.
Otherwise, you’re just indulging a predilection to be a jerk.
Regarding what I said above.
I swear I thought this was the Pit. I apologize for the error.
Even if this hadn’t been immediately after sex, if your girlfriend was making a joke about her own body then it takes a real jerk to “correct” her by criticizing her body.
If she was engaging in a little post-coital dirty talk then again, this was not the time to offer factual corrections and definitely not the time to complain about her genitals.
If her remark about having a tight vagina was not made in a joking/dirty talk manner then it seems likely to me that she was trying to bring up something serious but embarrassing – that intercourse was painful for her. But instead of listening to her, you went right to “Woman is in error, must correct!”
I’m not seeing any way to interpret this situation where you did the right thing, or even an acceptable thing.
The only person on Planet Earth obligated to “deal with all your shit” is yourself. Repeatedly putting people to the test as to at what point they will tell you to shove off is not normal conduct.
And your particular example was rather appalling in both nature and timing.
How *you *doin’? 
I count making one’s lover feel great about themselves as a person as part of someone’s skills as a lover. It’s not just about the sex act itself.
Give that poster a prize!
All you did was destroy that woman’s self-esteem regarding her sexuality. I’d guess it’s going to take a very caring partner to reassure her and get her past that horribly cruel thing you said. Despicable.
When she commented that she had a tight vagina, she was looking for a compliment. She wanted to hear you say it was the nicest, tightest vagina you’ve ever had.
What the hell is wrong with you?
I want my husband to be more honest and straightforward with me than he is with others because I want to clean up that toothpaste glob rather than having him just avoid me or the topic. You can stop using that cab company, after all.
But saying something to be an asshole is something else entirely.