Prefix support in Sequelize.js

Is there any way to support prefixed tables names when using Sequelize.js ?

Imagine I wanted to build a blogging platform so that each registered user would get his own blog and URL (subdomain). Now if one opens userxxx.mydomain.com he should get content from tables named userxxx_TABLENAME while opening difuser.mydomain.com would fetch data from difuser_TABLENAME etc.

I tried adding prefixes to models names eg: sequelize.define('userxxx_Post' ...) which could work but creates mess when it comes to many-to-many relations (table names become userxxx_Postuserxxx_Comment).

Is there any better way?

(I'm not exactly building a blogging platform on node.js but solution to this problem will be the same)