Presumably she'd figure it out, and instincts would take over. She had no way of knowing, but Trunks only had slightly more knowledge than her. Knowledge, not experience--because his life had held no room or time for romance and dating or anything like it. Which didn't mean he didn't know the concepts, or what was going on, or how hormones worked and stuff.

Just he lacked experience and knowledge learned from that experience.

Right then though, it was enough. Just the gentle press of lips against lips, breathing softly. Then shyly moving to wrap his arms around her, shoulder and waist. Keeping her close against him, warm and soft and lithe.