Sakura will probably need to tell Ino when they're beginning to date, only because she needs Ino's help with advice as well as a cover story when she does wanna stay out late with Kakashi or stay over with him for the weekend or something. Sakura will be putting a lot of trust in Ino for not blabing. In return, Ino knows before anyone else and Sakura pays for most of the lunches when they go out together to gossip.