It was that little black dress that had done it for him. The timing, the unexpectedness given her usual frumpiness, the proximity when she slipped her coat off her shoulders... It all lead inextricably to his mouth dropping open, eyes bulging and unseemly drooling - unacceptable for someone of his rank and age. Luckily the transformation from duckling into swan, closely followed by Sherlock's appalling manners, distracted everyone from his display of misogynistic excess.
Since then, he'd not stopped thinking about her and daily worked out elaborate reasons to visit the morgue. There had been the Bartlett Twins investigation where the case hinged on whether the mother had died from the stab wounds or the blows to her head. A memo took care of that. Then there was what the squad was calling the Bungled Burglary. The shape of the stiletto that killed the burglar could easily be found out from reading the report and did not require a personal consultation.
In fact he never followed through. Ok, so his marriage had been seriously on the rocks when he'd first caught sight of her in that dress - but now, well they were taking it slowly, but he predicted that he'd be back in the house by Easter - next Easter.
And he could easily find Molly. After all she only worked at Barts.