A first love, a "soulmate", like the boy who lives down the street, boy who you loved or dated throughout high school or adolescence, etc. Derives from title character of Dawson's Creek, the TV series.
"Oh, my highschool sweetheart...he was my Dawson..."
One of those guys who is sweet to his girlfriend, but still witty and manly. Not the white-as-snow knight in shining armor type, but a more byronic type of man. Derives from the best character on the TV show Dawson's Creek.
"What kind of guy is he?"
"He's sweet but cool...he's a Pacey."