Ernie half believed the whole thing was a joke. Draco Malfoy throwing a surprise birthday party for Colin Creevey? However, from what he could tell, Colin and Draco's friendship was sincere. A mind trip, but sincere all the same. Besides, he wouldn't miss Colin's party. They might not have been super close, but they were in the DA together and got on well enough.
He arrived exactly on time, but stuck himself in a corner as he waited for Colin's arrival.