affair
love affair

end
the affair ended happily

hit-and-run
a hit-and-run affair

honour
an affair of honour

kind
an affair of this kind

knee-deep
he is knee-deep in the affair

love
love affair

nucleus
the nucleus of an affair

open
the affair is still open

part
...in that affair

petticoat
petticoat affair

rest
the affair rests a mystery

white-tie
a white-tie affair