It's disgusting to betray your partner's trust.
Cory has a girlfriend who he is losing interest in and is developing an interest in another woman.
Cory wants to hang out with the other woman.
Cory is open to his partner about how he has been feeling.
Cory tells his partner that he is with a male friend of his.
Cory's partner is given proper notice and does not expect their relationship to endure.
Cory's partner finds out about the other girl and feels betrayed.