What do you call a person who chooses to ignore someone at specific periods of time

Imagine a person X who chooses to ignore his/her responsibilities and family at will, only to attend to them when he/she sees a tangible gain to be had out of it.

Selfish is one option, but I'm looking for something more specific.

You might call them a fair-weather friend:

Fair-weather friend:

Someone who stops being supportive or loyal when you run into difficulties and need help.

(The Free Dictionary)

Basically, a fair-weather friend is there for you when it's convenient for them, but when they'd actually have to do something for you, suddenly they disappear.

Self-centered. If the individual is acting out of spite, passive aggressive.