"Consenting Adults"
It began with Walter finding Integra alone in rooms, blushing furiously and muttering unladylike curses. Later came the spirited banter with the vampire, her small smiles, and his casual touches. Walter was unsettled by her growing fondness of Alucard.
He lectured her gently, concerned that Alucard had perhaps somehow misled her. Walter knew first hand that the vampire could be quite charming. He was surprised when she laughed off his concern, assuring him that she certainly knew what she was dealing with.
"Do you honestly think I'd be seduced by a handsome face and silver tongue? Your concern touches me, Walter, but there's no need for it. I'm hardly being lead astray."
Integra's words did not comfort him in the least. However, he did notice their increased discretion. He felt guilty letting sleeping dogs lie, but he'd long since realized she was instigating as much as Alucard. Walter couldn't help but also notice the vampire's remarkably improved behaviour.
He learned to ignore Alucard's self-satisfaction and the way he looked at Integra like she was the center of his universe. Walter turned a blind eye to stolen kisses and midnight rendezvous. He did not remark upon the occasional bruises Alucard's kisses left on her throat or shirts hastily and crookedly re-buttoned. Walter was a good and humble butler, after all, and who was he to deny his mistress her pleasure?