Multi master in one direction is indeed possible. There are many ways to guarentee that DML on a server does not get replicated back:

1. No "support" is generated for objects in the dB you want silent. Support is the process of building the replication triggers that operate replication.
2. No PUSH job on the silent side is set up.

Note that both databases are still considered masters.

ALSO, VERY IMPORTANT: know that if you do not propogate changes on one of the sites, your master sites are OUT-OF-SYNC! What does this mean to your business???