nhibernate bidirectional many-to-many association

i have category following description:

public category fan {
    open iset<client> contacts { get; stable set;}
}

i wish map contacts ability onto following table:

create list user_contacts (
    user1 uuid null,
    user2 uuid null
)

i wish map bidirectionally, i.e. customer1 total customer2's contacts, customer1's contacts collection should enclose customer2 (maybe wholly after entity reload). i that?

update certain i map left-to-right right-to-left sets following brew following during runtime, nonetheless it'll... hmm... untasty... there solution? any way, conclude unequivocally match, fryhard!