Bart tells Cathy that Melodie loves him and points out that Malcolm was obsessed with his own mother until she abandoned him and how much he hates seeing his own mother with Chris .
Cathy discovers Bart and Melodie 's affair when walking in on them having sex .
Bart tells Cathy that Melodie loves Bart and points out that Malcolm was obsessed with Bart 's own mother until she abandoned him and how much he hates seeing his own mother with Chris .
Cathy discovers Bart and Melodie 's affair when walking in on them having sex .