Inamorata

[Justin Bieber]

A woman whom one is in love with; a mistress.
[Inamorata] comes from Italian innamorata, feminine of innamorato, from the past participle of innamorare, to inspire with love, from in- (from Latin) [amore], love (from Latin amor, from amare, to love). A man with whom one is in love is an [inamorato].

[Oralee]

A persons female lover.