Let us tell you a love story. Oh goody!
He is Marcus Antonius Polemon Pythodoros, Polemon II of Pontus (also Polemon of Cilicia), Roman client king, descendant of Mark Antony (THE Mark Antony). He is in his 60s.
She is Berenice (also, for some reason, Julia Crispina), daughter of Herod Agrippa, King of Judea. She is in her early 20s.
Polemon is madly in love (after all, Berenice is young, hot, and rich), and Berenice herself is not about to pass up to chance to marry into Roman royalty. Especially since she has a dark secret... After her first husband died (she was married when she was bat mitzvah age), and her second husband died (he was also her uncle), she started to co-habit with... her brother. (Now, we don't know if it was just hearsay, but she clearly wanted the rumors to go away. So there.)
Berenice agrees, under two conditions: Polemon has to convert to Judaism (easy enough) and get circumcised (errr...) The old man agrees, and they live happily ever after!
Not exactly: the marriage didn't last. Berenice quickly dumped Polemon (circumcision and all), returned to her brother, and then shacked up with a man a decade younger. Polemon denounced Judaism (circumcision and all), and apparently became a Christian, before reverting to paganism.
Some love story!