It DID. It was a very touching and heart-warming haircut, believe me! Gerard's charmingly matted dirty homeless hair, and Frank gently cutting it! While Gerard half-cringed or something because of his traumatic life! I just wish she'd stuck around to let Frank give him a fashion makeover, or something. And probably share his bed. And teach him about the warmth of loving family dinners or something. I'm sure these scenes could not have been far behind.

sidles past the actual tattooing with his eyes shielded until he can hide in the soundproofed back room

YES, EXACTLY. I hope that is precisely what he does. That's why Frankie is completely in charge of things in the shop, because Gerard's hiding in the back room smoking and fidgeting and reading comics! He knows the front room is safe for sex because there's no way Gerard will come out and discover them!