Yeah you're right you're not saying he's a pedo, as you say in your op he was 21 and she was 17...so what's your point?
usa does have different rules to the uk. i believe if one person is under 18 the partner or whatever can not be more than 4 years older, i think if they are it can be stat ****. unless parents consent. im sure someone else will give the exact laws in pa