How to join parent table, with multiple parent field -- child table

[Denmas]

Since I am a newcomer in FM, and lack of English.. I've search in forum and cannot find solution.. 

I want to make solution with scenario here:
[parent-table] Agreement fields:

• regs, number
• signing party 01, text
• signing party 02, text
• signing bystander, text
• agreement topic, text

 

[child-table] CLIENT fields: 

• client ID, text
• client Name, text
• client Addr, text
• client Phone, text

 

The Final result I want is to make an agreement letter, that contain all signing-party in one record of Agreement tabel.
----
AGGREEMENT LETTER
today, have been met parties:
Party 01,
  Name  : Smith
  Address : London

Party 02,
  Name :  Alex
  Address: Roma

Bystander,
  Name : Emma
  Address: Indonesia

All parties will join to a project here :
...
...etc.

-------

How to achieve that? .. I mean, can a record in parent-table have multiple lookup to the child table.. (without using portal tool).
How to make a relationship graph?

All post will highly appreciated.

Thank you,

Totok