They may happily coexist in your phone, but Bumble and Tinder, two of the world’s most popular dating apps, are at war offscreen.

Last month, Match Group, which owns Tinder (along with Match.com, OkCupid and Plenty of Fish), sued Bumble for violating its patents and trademarks, and for a misuse of trade secrets.

Bumble quickly fired back. First, it published a fierce open letter that declared itself unintimidated. Then, it countered with a lawsuit of its own, accusing Match of asking Bumble to reveal confidential information under the guise that Match might purchase it. Bumble claims that Match’s lawsuit is an attempt to scare off other investors by discrediting the company.

That’s the quick version, but this drama goes back years. Here is everything you need to know.

Tinder and Bumble may seem like similar apps. There’s a reason for that.

Tinder and Bumble have a tangled history. Whitney Wolfe Herd, the founder and chief executive of Bumble, was a co-founder of Tinder.