The boy girls one is really difficult!
G/B:
Rozemarijn* and
Valentijnor Quirine* and
Constantinemaybe Tessel* and
Wessel, if they weren't so very close and impractical to use together.
G/G:
Rosalie and
Valerie if that rhymes enough for the law
or
Ramona and
Verona
B/B:
Roderick and
Alaricor
Rembrandt and Sybrand*
maybe
Arend and Berend*
*see submitted names for these.