It would be considered a crime. Possibly also needs to be considered in terms of grooming as the adult may be hoping to carry things further.

Is it abusive? Yes. The adult is abusing the trust of the minor. Even if the minor is aware there are a lot of other factors that come into play. Generally speaking a minor may be very smart but they can still be very vulnerable in other areas.

If anything is making a young person uncomfortable I hope they can find someone to open up to as it may save a lot of hurt later.

Of course that doesn't mean they have to be affected by what has happened but it's okay and understandable if they are.

What happens online can be every bit as hurtful as what happens in real life. Sometimes people forget that. They forget the people on the other side of the screen have feelings too.