For some reason, Twilight and Rainbow Dash's friends think they're dating even if they show absolutely no signs of doing so! They were just really close friends...
Prince Blueblood is often referred to as a somewhat hard to please stallion, earning a rather unflattering reputation outside the circles of nobles he is usually associated with. Ironically enough, much of the rumors could not be more wrong.
As the Crusaders cross the line into adulthood, the time comes for them to make some choices about what their relationships will become. It turns out that shared affection may be harder to overcome than any shared adversity could ever be.
When everyone around you still thinks of you as the evil conqueror you used to be, it makes it hard to make friends. Sometimes you just want to be held and told everything's gonna be alright.
It is not every day that you learn that a monster of legend is real, let alone friends with Rarity. If she had heard of the old stories, perhaps she would be more cautious. Or more daring. (RGRE) {Has first and second person versions}