Lyric discussion by chaidrinker 

Cover art for Grenade lyrics by Bruno Mars

I was once cornered by a bunch of guys who decided to play baseball with my head, knowing I had a concussion, who told me not to even think about getting help from the man I wanted because they had already spoke to him and he said he didn't care about me anymore, they could have me, and do what they wanted with me. That was more upsetting than the ball. He walked in on the situation and I thought I saw him walk away but to be fair I was distracted and only allowed a few brief glimpses because I had to maintain eye contact with the guy in front of me or have the ball grazing my temples or worse if I looked away. It was an ugly situation and when it was over I went a little hysterical on the man I was crazy about. I don't remember everything I said. I know I was upset.

Back to the song.. something happened that hurt her making her think he doesn't care so she's making him "black and blue" so to speak making him prove he cares about her. This song makes me cry because I would want to hear someone say "I would catch a grenade for you'.