Bravery is the choice to show up and listen to another person, be it a loved one or perceived foe, even when it is uncomfortable, painful, or the last thing you want to do.
Ted was wildly uncomfortable. He wasn't quite sure who Rachel was on a date with, but it didn't seem to be him. He'd contributed nothing to the outing; as far as he could tell, she could have brought an inflatable doll with her to the movie and had an equally good time.