Not even the exhaustion of the idea of making it further down the hallway was an excuse enough to interrupt the momentum. Because there was momentum and it was almost just as dangerous as he was. It shouldn't be happening, he should have left a long time ago. Not because he wanted to leave, and not because he didn't want to continue forward, but because he knew that he was capable of doing a lot of damage. A lot of damage people didn't deserve in more ways than one.
He didn't want to tarnish the moment with regret. There was a sanctity to it worth preserving. And while the gentleman in him wanted him to escape for both of their sakes, the feral part of him wanted to continue to be lead and to give in to the seduction. Natasha could have had any man on the planet, Bruce knew it, and he didn't think this was one of her tricks. There was no benefit here, even if it was an attempt to get intel. And he knew she was better than that.
The temptation of her lips against his was too much. He was in too deeply now, drowning in her touch and warmth. He couldn't have said no even if the rational part of his brain continue to tell him to do just that. "I could do that," he mumbled into the connection, brown eyes closed. His heart picked up some, and he felt a surge of energy flood through him.
Kissing Natasha was like heaven. But he wasn't meant for heaven.