Although you can’t plug a headphone splitter into an iPhone anymore, you can use your AirPods Pro (or a second pair of AirPods) to share audio with a friend when paired with any iOS 13 device.
If you own an iPhone, you've probably used it to listen to music through headphones on your commute home from work, or while using the treadmill at the gym. And generally, as soon as you unplug ...