I would much rather see Dream being dragged for one of his numerous lies than girls enthusiastically talking to him and then changing their minds. I think he was stupid for not making more sure that the girls are 18, and for talking to them at all, exactly because this kind of things happening, but I think he was just stupid not malicious.

From his perspective he must have just thought that he is talking to legal adults who seem enthusiastic to talk to him and there is nothing wrong with what is happening. It is possible he enjoys talking to young people because they are young, it is possible he enjoys that he has some power over them, but there is no proof of that. But some people act like these are the only reasons this would have happened.