"I hope so," came the mumbled response, and Starscream found himself fascinated by the difference in their colours, shape---he'd thought all humans looked alike. But really, once you were one, you saw all sorts of subtle differences. "I admit," he glanced back up, fingers slipping beneath the other man's waistband to rest against the warm skin of his hips, "that I'm a little scared of it."
He nuzzled the hollow of Skyfire's throat, fascinated by the delicate line of his collarbone, teeth nipping gently. He didn't know where such feelings were coming from---desire to leave a mark, perhaps, warring with an instinctive need to protect. Or perhaps it was human sexual instinct. Now that was going to be a fun aspect to explore. He wondered if Skyfire would give him that scandalised glance Starscream had always loved so much if he revealed just how utterly shameless he'd become.
No, no--- that wouldn't be a good thing. That had come after Megatron, after all.
"Human bodies are formed so strangely," he added at last, letting fabric slide away from Skyfire's hips, crimson eyes wandering the length of the other man's form, fingers exploring carefully.