Almost as good as sex, but different, Cain leaning into him and clinging instead of pushing and grabbing.

Cain's weight pressed into his back, hips grinding into him with the vibration of the engine.
And then the highway opened up, traffic light, huge gaps to weave through and really get Cain's arms wrapped around him. He cut a little close between two trucks and grinned into his helmet as Cain gave a startled yelp.