From The Daily Mail:
The red-headed singer who has collaborated with Taylor in the past may have been doing a different kind of collaborating after they ‘stayed in (her) room, just the two of them, until around 4am.’
A source told the publication that when the singer/songwriter left her room he looked ‘very happy’.
Apparently after their rendezvous, Taylor got her driver to take Ed away in the car she had used earlier in the day. ‘He looked very pleased with himself.’