She gives him an amateur handjob.

Zach gulped as Chloe bit her lip, suddenly realizing all the complications this might have

He inhaled deeply as she got on her knees, eyes wide, "C-Chloe"

"N-no. I kn-know what you're going to s-say, but I want this." To emphasize her point she grabs him a bit hard through his trunks, eliciting a gasp from him.

Zack nodded and lifted his hips for her, as she struggled to get them over his rigid cock. Her jaw dropped as she saw him throbbing, and he could hear the uncertainty in her voice as she smiled nervously. "Commando, as always? Why do you always put your s-soldier at risk of being seen?"

With that, she gripped his cock gently, as if she were afraid, and began to stroke it. He groaned softly and tried to fix her grip, but she was entranced, suddenly gripping harder and jerking as hard as she could, filling the room with the sound of her hand hitting his balls as she sat there, tongue out a little with her red hair plastered to her body and forehead. Zack can't help but wonder why he never found her attractive as he felt tension building in his loins.