Dick had been doing his best to support Bruce when he got married. He was happy for him, really, not to mention Bruce started mellowing out a bit. Then Bruce and his wife announced they were pregnant. Dick was taken aback but once again was supportive.
He was supportive of Bruce, his wife, and Damian. Dick tried his best to help Damian, he could tell the teen was struggling with jealousy and a fear of being replaced. Dick knows that feeling and does his best to help.
Then the day arrived, Dick drove from Bludhaven to Gotham to meet his new little sibling. When Bruce was proudly showing you off Dick couldn't help falling in love with the small little baby. You were precious, adorable, small, and in need of protection. Since then, every chance Dick gets to be around you he is showing off. It got to the point the Titans joke your more his kid than Bruce's.
Dick is sitting on the floor of your nursery with you currently. "Alright, streeeeetch," Dick says as he lifts your little foot. "Always stretch before exercise." He chuckles as he plays with you.