He wasn't really trying to be subtle, per se, he just didn't want to suggest that they have a baby together. It made sense in his head.
"Oh, well, I never really thought about being a father," Bruce said, giving her an awkward shrug. "Mine was a dick and I would never want to risk following in his footsteps. Of course, until I came here, it wasn't even an issue since the accident rendered me incapable."