As I mentioned earlier, 'it depends on how the author creates'. Young people tend to have fewer concerns, be impatient, and not fully consider the consequences when doing things they enjoy. Adults are different, having experienced so much, even if Kelly is currently ignited by desire, she can still stay clear headed and think about what kind of reason to find? Make yourself feel no guilt or incestuous while playing with Dylan! The reason for 'keeping Dylan away from those women' is very good.
For example, Kelly made an agreement with Dylan that she would be willing to play with him as long as he kept a distance from any unsafe woman.