Well, I promised to report in with the result. It's a surprise ending, if a bit anti-climactic after all your good advice and all my studying.

Girl's mom contacted the boy's family, who, it turns out, are churchgoing Catholics. (He rejects Catholicism.) After listening politely to the details, and then to the voice mails boy left for mom (did I mention the voice mails? - they were peppered with the "F" word mixed in with his "religious" ramblings), the boy's family wholeheartedly agreed that he was on a wayward path. The numerous corrective actions they intend include keeping him away from the girl (he's in high school; she's in middle school.)

Girl is still in love, but not embarrassed by the affair, and will move on. Boy's family will have to be in charge of his development, but they sounded concerned ands well-intentioned.

So it seems it will all work out.