Romeo and Wendy have been best friends for a very long time. They also have had a secret that they made when they were kids involving some special bracelets. When Natsu and the others notice the matching bracelets, they want answers.
Natsu doesn't get the groove of gruvia. (That was a bad pun.... Ok, I'll leave now)
Ugh this is why I don't want friends. They tease you, they make fun of you, even though its just fun and games it can hurt someones feelings.