In The Flash (2014),
Reverse Flash travelled back in time to kill Flash when he was kid. Flash followed him and saved his child-self once and returned to his own time.
Now, the question is: Why didn't Flash stay with his child-self or with Reverse Flash to save himself? Why did he return knowing Reverse Flash could go after his child-self again? In fact, Reverse Flash did get the chance to kill Barry and nobody was there to protect him. I hardly doubt that the future Flash knew that Reverse Flash would stuck and he would need his past-self to return and he wasn't psychopath enough to drop the idea of returning home over the idea of killing Flash.