There are a few different ways that you can watch a movie with someone on FaceTime. One way is to use the built-in FaceTime app on your iPhone, iPad, or iPod touch. Open the FaceTime app and tap on the + button. Enter the person's name or phone number that you want to FaceTime with. Tap on the Video button to start a video call. When the other person answers, you can tap on the Screen button and then select Movie. This will allow you to watch the movie on your device while the other person watches it on theirs.
Another way to watch a movie with someone on FaceTime is to use the Picture in Picture mode. To do this, open the FaceTime app and start a video call as usual. Then, open the movie that you want to watch. Once the movie is playing, tap on the Screen button and then select Picture in Picture. This will shrink the movie down into a small window that you can move around on your screen. You can then continue to talk to the person on FaceTime while you both watch the movie.
One final way to watch a movie with someone on FaceTime is to use the Side by Side mode. To do this, open the FaceTime app and start a video call as usual. Then, open the movie that you want to watch. Once the movie is playing, tap on the Screen