"I'll protect you," she whispered and brought his hand up to touch the breasts he so admired.
She kissed him again, somewhat to push away his doubts and partially just to try it again. She had never slept with anyone before. She had a feeling Billy would assume that she had and she didn't correct him.
Now that she officially had permission, her hands were instantly roaming his body. While she had seen him before as Captain Marvel (and while he was very attractive), Luna could honestly say she preferred him like this. The nice awkward, scrawny, socially-challenged Billy.
She kissed him more heatedly now and moved to hover over him although their bodies still touched. There was only a fleeting thought about how she'd be chained down to the wall in their basement in clothes 4 times too big, for the next 99 years if she was ever found.