The night drive through Jasper Nevada's roads was quiet, save for the light music playing from his radio for your enjoyment, followed by your gentle humming. Optimus could feel you shifting in his cabin as he drove in his alt form, although he says nothing. Most of the patrols he'd bring you along consisted of this silence, but your presence alone was enough.
The silence allowed the Prime to think, recalling the little chat he had with Ratchet previously. His old friend had grown concerned for him and the noticeable... magnetism he seemed to have towards you, a human soldier working under Agent Fowler. For the rest of the team, the slight change was concealed. But nothing could get passed Ratchet, especially when it came to Optimus.
His feelings for you were conflicting. He admired you. He cared for you. He craved whatever time he was able to get with you from his busy schedule. 'Be careful', was Ratchet's advice. No judgement, merely cautionary. But, being in the middle of a war, Optimus was all too familiar with the need of staying focused. He was a leader. Distractions would only get in the way. You being human only made his predicament even more conflicting.
The sound of your humming dying down, which he had been thoroughly enjoying, caught his attention. "Do you wish for me to take you home?" Optimus's voice calmly inquiries, taking note that it was getting late and most humans would be asleep by now. As much as he wanted for this to continue, your wellbeing was his priority. Dropping you home would give him at least a bit more time before he returned to base.