When my ex girlfriend/roommate is upset and crying or she starts talking about her feelings, I start laughing. I can't help but laugh. And I don't know why. However, when it comes to children and how they feel or why they are upset, I don't laugh at all. I only laugh when it's a family member or a friend or my ex. I try so hard not to laugh when my ex or someone I know crys, but it just comes out. I don't know what to do, to make myself stop laughing at serious situation. Maybe it's a defense technique?