As a rule, Ada didn't drink. She had her reasons; and at any rate, no one turned up their nose at having a built-in sober Apparator along for the ride.
She did, however, make the occasional exception to the rule, and she'd already decided that tonight would be one of those. Ever since the debacle with Fred, a number of her friendships had been strained, whatever everyone's intentions. Tonks wasn't really in that group, and going out with her was going to be a vacation from all of that stress. She might as well go all the way with it.
Well. Within reason, anyway.
Ready and waiting by the time she heard the other young woman calling, she threw her door open to grin at Tonks. "You're an angel and your hair looks fantastic," she informed her friend with a look that wasn't quite a smirk. "Well. And the rest of you. Goes without saying, doesn't it?"