Please tell me she's laughing bc of the Duke's frustration,,, and not bc deki is being sco...

I think it's the dukes frustrations I also think Medea is being cold towards dekis just to push him away from their father...... because to deal with the duke one would have to be ruthless and cold but dekis is just too good for his own good. If he continued living in the Solon's with his personality he would eventually die from his father's beatings.... I think that's what Medea is trying to prevent by making him think she doesn't love him anymore