Why come in all 7 long years we never see eric have a steady long love relationship with a girl he loved like cory on the show ???

https://www.youtube.com/watch?v=n3eJkf4erbI
https://www.youtube.com/watch?v=n3eJkf4erbI
https://www.youtube.com/watch?v=n3eJkf4erbI