Teen age runs from 13 to 19 but you haven't stated where she fits in. If she's at the older end of the scale it may well be appropriate. Does she have an active sex life? Do her parents accept that?
We're no longer living in the 1950s.
If she's younger, of course, it's a whole different ball game and, no, that would be quite irresponsible.
I am confused .. Is being left alone with the boyfriend the concern .. Or is a 15 yr old girl with a 19 yr old boyfriend the concern? I don't think it matters if the boyfriend is also 15, or 16 or 17 .. Or any age ... If there is a concern .. There is one because they are irresponsible .. And THAT has less to do with age than you'd think. A 15 year old boy can have the exact same 'intentions' as an 19 year old. It's not about the age as much as it is about the individual.
If he allows her to even have a boyfriend of any age .. then he must trust her.
That is weird! Unacceptable! Even if he does trust her, still... Older boys think with their ****. Sorry, it's true. Actually, all teenage boys do.
It depends on a lot of things.
For example: How long has the family know the boy? And does HE think of himself as her "boyfriend" - or does she just have a crush on him?
(Just remembering when *I* was 19, and the neighbor girl (15) had a crush on me and tried to hang out with me all the time. I knew what was going on, but thought of her more as a little sister than anything else.)
Didn't find the answer you were looking for?