It's easy to talk about the many, many, MANY times that Zeus fooled around and got some poor girl in trouble--forget a little black book, the guy needed a whole set of encyclopedia-sized tomes to keep track. But by no means was he the only god sowing his wild ambrosia whenever, however, and--unfortunately--wherever he darn well pleased.
But a tale from Ovid's Metamorphoses gives a twist to another story by explaining how it all began, namely the tale of Medusa and her sibilant snaky locks. You probably know about how Perseus borrowed a shiny shield, snuck into her cave and tricked her into turning herself into stone by looking at her own reflection. But where did she get that snake hair in the first place? Let's go to the source:
"Medusa once had charms; to gain her love
A rival crowd of envious lovers strove.
They, who have seen her, own, they ne'er did trace
More moving features in a sweeter face.
Yet above all, her length of hair, they own,
In golden ringlets wav'd, and graceful shone."
So she was totally smokin' hot at one point, with the kind of hair that most people can't get with a closet full of beauty products. No snakes in sight. What happened?
"Her Neptune saw, and with such beauties fir'd,
Resolv'd to compass, what his soul desir'd."
Oh, Poseidon, you sly dog. But just gettin' your freak on with a lady usually wasn't enough to get her punished, right?
"In chaste Minerva's fane, he, lustful, stay'd,
And seiz'd, and rifled the young, blushing maid."
Ah, there it is, in 17th century Olde Timey Speak: they did the dirty deed in Athena's temple. I don't know about you, but I wouldn't want my uncle putting the moves on someone in my room, either. And Medusa was supposedly a priestess of Athena at the time, which of course only made the problem worse, what with the whole mandatory virginity clause. So what did Athena do?
"The bashful Goddess turn'd her eyes away,
Nor durst such bold impurity survey;
But on the ravish'd virgin vengeance takes,
Her shining hair is chang'd to hissing snakes.
These in her Aegis Pallas joys to bear,
The hissing snakes her foes more sure ensnare,
Than they did lovers once, when shining hair. "
And there you have it. Because Poseidon couldn't keep his trouser snake in his, er--well, he probably wasn't wearing anything because he was god of the OCEAN, but you get the point--poor Medusa ended up with snakes on her head. She then experienced what is arguably the longest pregnancy ever because it wasn't until Perseus cut off her head that two kids jumped out, one of which was the fabled Pegasus.
On the plus side, she got to grace Athena's shield as a really creepy emblem. The downside: obstacle course of statues whenever she had to leave her cave to potty.
Meanwhile, Poseidon was off catching some gnarly waves en route to his next conquest. He may or may not have high-fived a few dolphins along the way, but Ovid is suspiciously silent on the subject so we'll just have to imagine it.