The Mad Herringtons by Jane Myers Perrine
The antics of Aphrodite's passionate parents embarrass her, and she unfortunately finds the rest of her family almost as bad. Young sister Athena is always kissing men; Terpsichore runs a literary salon and is highly unconventional; and her brother has got into a scrape at Cambridge. Aphrodite wants to marry a dull, sensible man to escape all this, and she also wants to escape the surprising attentions of the attractive Lord Warwick.
However, in spite of becoming engaged to Mr Horne, she finds that escape is not so easy. When she travels to his country house to meet his ghastly mother, she discovers that Lord Warwick and her sisters are there too! Her brother is pretending to be an Italian aristocrat!
This was a highly amusing Regency romp by Jane Myers Perrine with delightful main characters. The only trouble was some of the modern language. I doubt that a Regency heroine would have called a man 'gorgeous'!