Englishparamour
noun
his stepfather's paramour:
lover, beloved, significant other;
mistress, girlfriend, kept woman, other woman, inamorata;
boyfriend, other man, inamorato, gigolo;
informal sugar daddy;
British, informal bit on the side, toy boy;
British, informal , dated fancy man, fancy woman;
historical hetaera, odalisque;
archaic concubine, doxy, leman, courtesan, cicisbeo.