While not arousing, the sound was definitely adorable, and Optimus hummed into Cliffjumper's mouth with amusement. He took advantage of the opening to testingly slide his tongue across the minibot's own, tilting his helm to deepen the kiss.

Hand sliding up and down Cliffjumper's back, he slowly increased the pressure, sliding the smaller mech closer to him and simply snuggling close with a rumbling purr.

He wanted Cliffjumper to learn, and be comfortable. He didn't need to rush anything. They had plenty of time.