The bizarre practice of throwing sex toys onto the court is becoming increasingly common at WNBA games as these disruptions go viral online, officials said.

Lance Stephenson is demanding an end to the sex toy-throwing chaos at WNBA games -- not just out of respect for the players, but also for the young fans in the crowd. The longtime NBA star made things crystal clear to TMZ Sports this week ... following a fourth incident where a dildo was launched onto the court during a W contest.

A sex toy landed near Indiana's Sophie Cunningham after it was thrown from the stands in L.A. while the Fever played the Sparks in the latest of several such incidents.