Remember when I said Hera was Zeus' first wife, I lied.
No, Zeus' first wife was actually a titaness of wisdom named Metis, but whatever happened to her you ask, well the title kinda tells you what happened. Yeah, Zeus actually ate his first wife. And she was pregnant with his baby no less.
Zeus the pioneer of the Vore fetish
You see after Zeus fucked Metis and she was expecting a child and so Zeus went to consult the Fates about the destiny of his child. The Fates told him that if it was a boy, he would usurp his father of the throne, but if it was a girl, Zeus would remain in power. Now because he did not want to risk the consequences so he thought it would be smart to get rid of the child.
Wife can you check if there is anything stuck in my mouth
Now in the days before immortal killing coat-hangers (Wow that is dark), the gods usually resolved there problems with their unwanted children by eating them (see Kronos). But Zeus didn't tell what he was going to his wife, but instead told that he wanted to play a little game. Since the gods and titans could do anything they wanted, Zeus said he wanted to see Metis change into any shape that he desired. After a few practice rounds, he told Metis to turn into a fly and as soon as she did this, he ate her.
Ow my fucking head!
But Metis had her revenge, she went up into Zeus' head and began banging up armor for her child. This gave Zeus huge migraines for the next 9 months and then finally he ordered Hephaestus to open up his skull and out came Athena, fully armored in all glorious hotness. So I guess there was some benefit to Zeus' douchebagerry.