What are we supposed to say about someone else who just never makes time to RP with you that you are linked to @sunny?
How do I explain that I haven't seen or spoken to my spouse about anything of import in IC weeks or months, without making a decision for them? Do I have to invent a plot by which despite my being present in the setting, I was somehow not available either?
I agree that you should really try to avoid making up events or motivations for someone else without express permission.
However, the assumed regular interaction suddenly has to be removed with a reason, and that reason will involve the other person. Unless there is a really convenient way to remove the relationship, such as it was never revealed to anyone.
A player has a responsibility to another player they have linked themselves to, and just saying no you can't make decisions for me while you actively make decisions to avoid having scenes or giving a way out is plain being rude and immature.
The question is how do these players best respect one another's "rights" and prior commitment if they have decided to end/alter it?