“This is very unusual,” says Luke Hunter, a researcher and chief conservation officer for Panthera, the global wild cat conservation organization, who wasn’t involved in the filming. “I’ve seen two male leopards attending the same female leopard when she is in heat, but not vice versa.”

Guides at Londolozi Game Reserve, adjacent to Kruger National Park, spotted the unusual arrangement. The guides know the leopards in the area, and note that the females are sisters, born three years apart.

“Because they are related and clearly know each other, they tolerate sharing,” Hunter says. “If two unrelated territorial rival females came together, I’d expect fur to fly.” (Watch: “Rare Leopard Cannibalism Caught on Video.”)

Unlike female lions, which tend to become