In the animal kingdom there are countless examples of the male being killed & eaten by the female right after mating. You'll even find times that they'll do it DURING mating. This usually occurs in species where the female is much larger than the male. You will NEVER find the reverse even after she has given birth. In the species where they do not kill & eat the male it is only for one reason. Because they are incapable of winning a fight against the male.

When they are incapable of winning a physical battle with the male, a majority of species females will procure protection and resources from the him. If you can't beat him, manipulate him into being a slave.

Entertain NO NONSENSE about females being the less aggressive and peaceful sex. It is inaccurate and untrue. Nature doesn't lie.

My Advice: Don't be eaten. Don't be manipulated. Men... actually... Males of all species: GYOW

EDIT: Someone wanted an example outside of Spiders. Here's Snakes and Octopi - in that link a scientist actually had this quote : “It’s probably not the male’s preferred outcome,” Scheel says. “But if you think about it…contributing his calories to his offspring doesn’t do any harm [to the species].” HAHAHAHAHA. SO FUNNY. I FORGOT TO LAUGH.

For more examples just follow any animal with a large SSD sexual size dimorphism. Actually, now that I think about it this may be the reason for the West's Fall. The women are just getting bigger than us LOL.

https://news.nationalgeographic.com/2017/02/anacondas-sex-death-brazil-mating/

https://blogs.scientificamerican.com/octopus-chronicles/female-octopus-strangles-mate-then-eats-him/