c# - Remove element of unilateral many to many relation -

for mapping below:

hasmanytomany(x => x.secondobjectslist)                .parentkeycolumn("firstobjectoid")                .childkeycolumn("secondobjectoid")                .cascade.merge()                .cascade.delete()                .table("firsttosecond"); 

the second object doesn't know first, i.e. doesn't have property firstobjectslist, doesn't need know second objects exist.

i need delete first object, there entry in many many table.

what approach?