...and in that time the two went from close, to closer.
Here's a quick look back at how things evolved, from the days of their first solo team-up, that started in the pages of Detective Comics #400.
Robin eventually went to work with the Teen Titans as they came back as the New Teen Titans, with Cyborg, Starfire and Raven, and Batgirl mostly kept to herself, being in semi-retirement.
Dick eventually changed his identity to Nightwing, then parted from the Titans for a while, landing in Bludhaven, while Barbara had been shot by the Joker, being confined to a wheelchair, and helping the Suicide Squad, Batman, the new Robin (Tim Drake) and Azrael as Oracle (an online personality Barbara created to help heroes against the ever growing legions of villains).
Birds Of PreyBlack Canary (Dinah Laurel Lance) who had been suffering depression and a lack of direction since the apparent death of Green Arrow (Oliver Queen). Oracle used her as her field agent, allowing Barbara the ability to have someone working directly to right wrongs (and giving Dinah a chance to do good and get on with her life).
Nightwing also used the services of Oracle, but, on one particular day, Dick decided to help his friend, Babs, relax, taking her up in the air for a special time (helped with a harness) allowing Babs to swing through the air (all in the pages of Birds of Prey #8 of August, 1999 by Chuck Dixon, Greg Land and Drew Geraci, under a cover by Land and Brian Stelfreeze).