It's not as problematic as you guys make it to be. Most of the time time I would be against such age gap (even 2 years, for example 16 and 18), but in this case it's quite different cause they know each other since they were little kids. There is no manipulation involved like in most cases when older partner is looking for younger partner, usually being adult themselves. There still is a matter of different brain development but here it seems like conscious decision, not a result of grooming.
It's not as problematic as you guys make it to be. Most of the time time I would be against such age gap (even 2 years, for example 16 and 18), but in this case it's quite different cause they know each other since they were little kids. There is no manipulation involved like in most cases when older partner is looking for younger partner, usually being adult themselves. There still is a matter of different brain development but here it seems like conscious decision, not a result of grooming.