The thought of ducking into an alleyway with anyone tensed the part of Tonks which, trained by Mad-Eye, was on constant vigilance. Of course, there was a fine line between constant vigilance and paranoia. One she was nervously walking every day of this war. Still, the question hung in the air. Did she trust him? She clearly did. He had put her on the case, he wanted to speak to her outside of the Ministry. He didn't trust them any more than she did. She had worked with him for years.
Her eyes stared up, searching his own deeply for a few heartbeats. He could almost see those thoughts crossing her gaze within that few seconds before she finally just nodded. "Of course I trust you, Gawain. I would not be here if I didn't." Tonks finally confessed, his first name giving the words an oddly intimate hint. This was no longer boss and worker -- this was conspiracy. Conspirators. The Ministry had made them such.
So she ducked into the alleyway with him, heart beating hard in her throat. If she was wrong he could take her straight to Yaxley, or even Thicknesse. Just the small intimations between them could be read as her being a dangerous creature. She hoped she wasn't wrong. She even closed her eyes a moment before they apparated, almost afraid to look.