talking about 'legal' sex with teens between someone and a teen who is legally permitted to have sexual relations with that older person and not have the older person be subject to criminal charges.

Sexual relationships with certain 'teens' is illegal if you are x years older than they are OR are in any sort of authority position with them like a coach and that all depends on if the teen is old enough to have sex 'legally' with anyone in the first place ie some 16 year olds can have sex with other 16 year olds 'legally' but not an 18 year old.

I don't know the particulars of that state's laws but just about everywhere you can't have sex with any teen 16, 17, 18, 19 if you are in a position of authority over them at say a school.

The teens talked about here may not have been 'underage' for sexual relations with a 18 or 19 year old who went to school with them so they are not automatically 'underage'.

Any link to that law that mentions 19?

The OP wasn't suggesting that 19 is the legal age of consent anywhere.

I had a assistant football coach in HS in CT who was somewhere around 23-25 who was arrested and fired as a teacher in a neighboring school for dating one of the 19 year old cheerleaders in my graduating class. He wasn't even her coach, just an authority figure.

He pleaded it...no criminal conviction in exchange for surrendering his teaching certificate and agreeing to no longer work with teens or coach or anything of that sort. (My impression is that the DA had doubts the charge would stand and/or the statute was legal.) Her parents didn't really want to press charges anyway because he and the girl were planning on getting married. It was the AD that called the cops because he was a mandated reporter and fired the asst. coach immediately.