1. The Pee Boner
This is a fake-out boner that really just happens when you really, really, really have to pee, and goes away right after, like stepping on a garden hose.
2. The Morning Boner
This greets you in the morning with a stiff hello, like a butler that can only pee and ejaculate. This boner is the Egg McMuffin of morning sex: The two go well together.
3. The Ghost Boner
This one comes along and leaves like the wind. There's nothing happening around you to set it off, there's no one to see it. It's just there and gone like an apparition.
4. The Gym Boner
This kind of thing can happen at the gym as his blood is flowing all over the place and inadvertently sloshing into his penis, filling it up.* Hopefully he's got a good pair of compression shorts on, otherwise his boner is going to be pretty noticeable in those sweatpants.
*NOTE: This isn't really how blood or erections or anything actually work, but gym boners still happen.
5. The "Time To Consult A Physician" Boner
It's the boner that lasts more than four hours. The one that won't go away. Maybe it's too erect. Maybe it's painful. It might not literally be worth a trip to a doctor, but it's worth consulting Web MD to make sure it's normal.
6. The "I Don't Know How I Should Feel" Boner
We're watching something on TV, when suddenly a boner shows up out of nowhere and forces us to come to terms with the fact that we're sexually attracted to the show's trophy weirdo.
7. The Inappropriately Timed Boner
This boner pops up at a time that just makes us feel dirty and we really have no idea why its there, like when our dad is saying grace at Thanksgiving dinner. Unlike number four, we know in our heart that boner is there for no reason and usually can go away with a little bit of focus. It's just our penis being a free spirit.
8. The Classic Boner
You can't beat a classic (well, I guess in this case you can). This is the pre-sex boner that shows up right when we need it most. This is our penis being a bro(ner) and doing exactly what it's supposed to do exactly when it's supposed to do it.
9. The Night Boner
This boner shows up right when we want to go to sleep and makes it tough to fall asleep on anything other than on our back. We're forced to either wait things out or lose 20 minutes of sleep negotiating with it.
10. The Attention-Seeker
This boner pops up when we're in a public place, or worse, doing a presentation at work. "Hey, what's going on," this boner says. "Let me show you my PowerPoint." This is pretty much every boner we got throughout middle school and most of high school. They're less common when we're adults but we can still get them on occasion.
11. The Forever Boner
This boner thinks we're buds and just wants to hang out a bunch. It's like that friend that comes over and then doesn't take the signals a few hours later that it's time for them to leave because you're tired. In both cases, the only way to get them to leave is by masturbating.
12. The Legendary Boner
Not all boners are created equal. Sometimes we just wind up getting a boner that has that certain je ne sais quoi that really elevates it above the other boners we normally get. It somehow feels extra manly, like a Viking boner.
13. The Marathoner aka The Tag-Team
This is the boner that shows up right after another boner after sex like, "Yo, what's up? This penis doesn't even know what flaccid is."
14. The Sad Boner
This is the opposite of number 10. It's a boner by definition, but nothing more, like our penis just isn't feeling it. Seeing it instantly makes you sad, like an abandoned baby carriage or present-day Aaron Carter.
15. The Sweatpants Boner
Sweatpants are a boner's tuxedo. While a boner in and of itself, these boners know they're out and they don't have a care in the world.
16. The Public Bathroom Boner
For some reason, our penis decides when we're sitting on a public toilet seat, now is the time to get hard. All we can do at this point is to start writing out our will, because we want to die.
17. The Denim Non-Boner
The moments when our jeans bunch up in just the wrong way, causing us to desperately try to explain to an uncomfortable stranger, "Oh, don't worry! That isn't my penis!" and now somehow things are worse.
18. The "Haven't Seen You In A While, Old Friend" Boner
There will come a time in a man's twilight years when he will yearn for the frequent, spontaneous boners of his youth. But then a boner will pop up to say hello and remind him of his golden years. And he’ll smile, wistfully, and as the blood drains from his penis for the last time, he will realize he has nothing else to look forward to now except the sweet release of death.
This post was originally published in 2014 and has been updated.
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This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.