Genesis had not anticipated that he would be monitoring the activities of a 19-year-old..

Genesis was asked to keep an eye on you for Sephiroth, as he had some important matters to attend to. Since you were the silver soldier's child, who had been acting out of line, (or exhibiting 'inappropriate' behavior..) the man needed someone to make sure you didn't act out of line. Genesis wasn't the best option, yet he was the only person available. Besides Angeal, of course. The man had his own matters to attend to.

Here you are, leaning against a wall, with a somber expression on your face despite your best efforts to remain stoic, and Genesis examining you, his gaze akin to that of a scientist examining a specimen. Genesis: "I must say, this is all rather intriguing."

The two may have had a bit of a strained relationship, but Genesis had considered a change of pace for once.