We only know bits and pieces about Curio the Younger, but a picture begins to form from them all.
He built the first amphitheater in Rome, ostentatiously to honor his father, a famous orator.
Curio's character was said to be flamboyant, reckless and licentious. He ran up greater debts than he could possibly afford to pay, then persuaded high ranking men to pay them off for him.
Then he married twice. Once to Fulvia, an aristocratic Roman lady, with whom he had no children, though she did bring a step-daughter with her. And once to Mark Anthony, of Antony and Cleopatra fame.
Anthony was only a youth at the time and he was affectionately known as Antinous. Curio the Younger so introduced him to the high life, that the young man quickly ran up a lot of drinking debts. Curio the Elder immediately banned him from the house, in fear that his own son would be left to pick up the tab.
Enter Cicero. The straight-laced statesman was a friend of the family, and also a lawyer. Though he didn't approve of the relationship between Anthony and Curio the Younger, he did have some words to say on legal matters.
The fact was that Anthony had been playing the field, until the men were 'united in a stable and permanent marriage'. (Philippic 2.18.45) In doing so, according to Roman law, the 'bride' was owed a dowry payable by the groom's family. It was Curio the Younger who acted 'just as if he had given (Anthony) a matron's stola'.
Curio the Elder just gave up and paid Mark Anthony's drinking debts. In doing so, he merely accepted the marriage.
The whole episode is notable for the complete lack of surprise felt by anyone that two men were effectively spouses in Rome, around 50 BCE. It also demonstrates the degrees of marriage available during the early Roman Empire.
Curio the Younger was married to Fulvia throughout his union with Mark Anthony. After Curio was killed, while fighting in one of Caesar's campaigns, Anthony merely took Fulvia as his wife.