Applejack has brushed her mane, put a ribbon on her hat, and there's a sway in her step. Most ponies just want to know who the special pony is.
Rainbow Dash doesn't buy it. Love is mushy, and AJ isn't mushy. Love means liking somepony more than her friends, and AJ would never like another pony more than Dash. Love means missing a game of horseshoes to go tell a pony that she's in love with them, and if there is one thing Dash is sure of, it's that AJ is not going to miss that game... no matter what Applejack thinks about it.