one and only
1. adjective A phrase used when introducing someone to emphasize that they are famous and uniquely talented. It gives me great pleasure to welcome the one and only Oprah!
2. noun One's only true love. Of course I'll stay true to you while I'm gone—you're my one and only!
my one and only
one's spouse or lover. (See also the one and only.) Look at the time. I've got to get home to my one and only. You're my one and only. There is no one else for me.