It is a question older than time itself: Why do women stop giving blowjobs to guys they used to love going down on?

It has baffled generations of men who enjoy receiving oral sex. It's like, one day your life is full to bursting with blowjobs, but then, just as suddenly, one day she just stops giving blowjobs. Or maybe they taper off until they're gone.

It probably feels like she just doesn't like you that much anymore. And that sucks.

So let's demystify this, shall we? Because we know it's not usually about how much she loves you.

RELATED: 12 Brave Women Reveal What They Really Think About Giving Blowjobs

If a woman has stopped giving blowjobs, the best thing you can do is talk to her about it if you want blowjobs back in your life. She will probably give you one of these common reasons for why she doesn't give you blowjobs anymore.

8 Reasons Women Stop Giving Blowjobs

1. You don't ask for blowjobs anymore.

Oral sex is a great way to use positive reinforcement.

If a woman has been giving a guy unsolicited amazing blowjobs and he never asks for them, she's going to assume that he doesn't want blowjobs anymore. It's not a game, it's not laziness, it's a reality.

If he likes it, he'll ask for it, or at the very least he'll ask why it isn't happening anymore. She isn't being withholding, she's trying to read your mind and give you what you need.

2. You won't kiss her after she gives you a blowjob.

Look, a penis doesn't taste like chocolate mousse. (If it does, please send that penis my way.)

We get it, a penis tastes like a penis, semen tastes like semen, and women don't care. We give blowjobs anyway. But when the guy we're giving blowjobs too refuses to kiss our mouths after blowjobs, it's rude and disrespectful. Plus, it makes us feel gross.

As a rule, if you want a woman to keep giving you blowjobs, don't make her feel that putting your mouth to hers after she's put her mouth on your penis is a totally nasty thing.

We all know dudes would suck their own penises if they could, so let's not get prissy, okay?

3. You never reciprocate oral sex.

Oral sex is a give and take. I give you a blowjob, you provide me with some stellar cunnilingus.

A woman is not going to go out of her way to give a man a blowjob if he never performs oral sex on her. Why? Because it isn't fair.

When we go down on men and they refuse to go down on us, it's telling us without words that they don't like our vaginas. Refusing to do so makes us feel like our vaginas are dirty when actually the opposite is true.

Sure, not all women love receiving oral sex, but if you haven't been going down on your woman and you're wondering why she isn't giving you blowjobs anymore, that might be a great place to start.

4. She doesn't like giving blowjobs or it's uncomfortable.

If a woman doesn't like giving blowjobs, she might just stop. This is her right. You can't force her to change her mind. That isn't your right.

But, as her sexual partner, you are definitely entitled to a conversation about how she feels regarding blowjobs, especially if she has stopped giving you blowjobs out of the blue.

Talk to her about it, and see where her head is. Bonus points: there's nothing sexier than a man who listens.

RELATED: 5 Reasons I Hate Giving Blow Jobs (And I'm Not Even Sorry)

5. You can't climax from a blowjob.

It might shock you, but not every guy can have an orgasm from oral sex alone. They might love the way it feels, and be down to be on the receiving end from time to time, but that doesn't mean it's how he reaches an orgasm.

If a woman has realized this, she might think she's doing you a favor by skipping what doesn't work and going straight for what does!

6. There's no time for fun stuff like oral sex.

When you've been together forever, and you have kids and jobs and the gym in the morning, sometimes you've got to streamline your sex life. This applies to blowjobs, too.

She might like giving them just as you like receiving them. But if orgasm for you both needs to happen fast, she might be skipping them to make the most of the limited time you have together.

7. Your semen tastes bad.

If a woman stops giving you blowjobs, there's a chance that the way your semen tastes might be to blame. Semen that tastes bad is enough to put any woman off blowjobs for good.

If you suspect this is the issue, ask her. If she says yes, look at where you can make changes in your diet to help make your sperm taste better. Odds are it will improve a whole lot more than just your sex life.

8. Her knees hurt when she gives you a blowjob.

Guess what, guys. Being on our knees hurts after a while. There's no fat padding there!

If you think your woman is no longer giving you blowjobs because her knees hurt, try changing your sex positions. There's more than one position when it comes to giving a blowjob.

You could also buy her kneepads, but that seems like a very callous and aggressive gesture to me.

RELATED: What Science Says About The Benefits & Risks Of Swallowing Semen

Rebecca Jane Stokes is a freelance writer and the former Senior Editor of Pop Culture at Newsweek with a passion for lifestyle, geek news, and true crime.