MVC EF get many-to-many relationship table

MVC EF get many-to-many relationship table

I set up my many-to-many relationship in EF. But I can only refer to the
main tables, not the bridge table. How can I refer to the bridge table?
for example:
User: UserID, name
Group: GroupID, group
UserGroup: UserID, GroupID
I can refer to the User table and Group table by typing
context.User.(some linq expression)
context.Group.(some lin1 expression)
But I cannot refer to the bridge table by typing
context.UserGroup