He wasn't really thinking the moment he blurted out those words to her. It just felt right. They were on a Team Mission. She basically took down a whole ass army on her own, and there she was, her face covert with dirt, her hair was a mess, she was panting from the outburst of energy, he was helping her get on her feet and giving her some fresh water. She just looks at him with that smirk of hers that drives him crazy and asked.
"What?"
"I love you." -Those three words that can change a person's life. He saw how her cheeks got coloured with a rosy pink. He has always heard how those three words were the most important ones in the world.
"I love you too." -Until she beats his three words with her four words. People are wrong, those four words annihilates his three ones.