2 characters on 1 account
No its not possible, you need a 2. account to play together. Also its forbidden to share the account with someone else.
ArenaNet Communications Manager
You will each need your own account to play Guild Wars 2. Please also be aware that account sharing is a huge risk for both of you, and it is against the User Agreement.
Gaile Gray
Communications Manager
Guild & Fansite Relations; In-Game Events
ArenaNet
Communications Manager
Guild & Fansite Relations; In-Game Events
ArenaNet