Good question. It wasn't like he never slept with Torchwood employees, just Ianto was, well, Ianto.
Flirtatious as hell and with a wicked sense of humour, but locked down so tight that Jack didn't know a single thing about the man outside work. Didn't even trust the personal file.
And besides, there was Brant. Not that they'd ever discussed anything like sexual fidelity, but right then, he kind of didn't want anyone that wasn't Brant.
"Kind of involved with someone right now," he admitted, watching Jack carefully. "You?"
Because if he couldn't ask himself about his sex life, who could he ask?