Caroline in the City

This is the first mention of Julia, the love of Richard's life who broke his heart. Julia would later return at the end of series 2 and throughout series 3. It's also the first mention of "Sincere Amore" the love you never have to question, which would crop up again on a few occasions. It could be considered an early indication of a connection between Caroline and Richard that Richard mentions Sincere Amore to Caroline and then she uses that as a reason not to be with Del only a few minutes later.