How To Implement M:N Relationships Between Classes In Code

Current i'm developing an application track storage of an item.in it abusiness rule says an item can be moved to more than one warehouses. Also i need to keep the history of the Item's history, Thereefore i need to create two entities,"Warehouse" and "ItemsHistoryOfLocations". I have developped an static class diagram to show the relationshop.These are the relationship rules between the classes:

1. A warehouse could be in an Item's History of locations.

2. A warehouse could be in many Items' History of locations.therefore in the forward relationshop -- 1..*

3. In an Item's History of locations, there must be at least one warehouse4. In an Item's history of locations, there can be more than one warehouse

Therefore in teh backward relationship -- 1..* Therefore the relationship betwween teh classes is a M:N. In another Object oriented scripting languaage when ever, and M:N relationship is found between classes, their relationship is slit and put a collection class called "MemberKeyDictionaries" as the bridging entity.But in C# / VB, should we create these collection classe. IF NOT, then how should i modify my class diagram to implement this M:N relationship? and h0w do i implement this M;N relationship in code?