Match Group, parent company of popular online dating app Tinder, is suing rival Bumble, alleging patent infringement and misuse of intellectual property.
The suit alleges that Bumble "copied Tinder's world-changing, card-swipe-based, mutual opt-in premise," according to TechCrunch.
Bumble was founded by CEO Whitney Wolfe, who was also a co-founder of Tinder.
Wolfe had earlier sued Tinder alleging sexual harassment.
The lawsuit from Tinder accuses former employees Chris Gulczynski and Sarah Mick, who now work for Bumble, of copying design elements.
"Bumble has released at least two features that its co-founders learned of and developed confidentially while at Tinder in violation of confidentiality agreements," the suit from Tinder added.