Here's what you can do:
Let's say you have 2 events, "cat" and "dog," and when you press Enter on a person, they move right and left respectively.
1) Double click to open the event commands on the person to activate the event.
2) On the event commands, page 2, select Move Event.
3) Move the event "Cat" --- right.
4) Click OK.
5) On the event commands, page 2 select Move Event again.
6) This time, move the event "Dog" --- left.
7) Click OK.
As long as you don't have some command in between them, the events will both move at the same time. Usually, having a message pop up right after the Move Event command will pause the entire event until the message is complete. Just put the message after the events are moved.