Gillian Anderson's relationship needs are "non-negotiable".
The 51-year-old actress - who has been in a relationship with screenwriter Peter Morgan since 2016 - has admitted that starting a relationship whilst in her 40s was distinctly difference to finding love in her 20s.
She shared: "It's very different. I think you are more fully formed, especially if you have taken time out of previous relationships to find yourself.
"Early on after the break-up of my last relationship and before my current one, somebody encouraged me to write a list of needs and wants in a future partner.
"Needs are non-negotiable. If you go on a date with someone and realise they won't meet, say, three of those needs, then they are not the person for you. It may last as a relationship, but it won't make you happy.
"Wants are easier, not more frivolous per se, but easier to deliver. Doing this made it clear to me going forward who would be good for me in a relationship.
"And there is a new creativity nowadays to what a relationship should look like, too."
Gillian - who has kids Piper, 25, Oscar, 13, and Felix, 11 - doesn't actually live with her partner, and she thinks that it's ultimately beneficial for their relationship.
The actress told the Sunday Times newspaper: "My partner and I don't live together. If we did, that would be the end of us. It works so well as it is, it feels so special when we do come together. And when I am with my kids, I can be completely there for them.
"It's exciting. We choose when to be together. There is nothing locking us in, nothing that brings up that fear of 'Oh gosh, I can't leave because what will happen to the house, how will we separate?'. I start to miss the person I want to be with, which is a lovely feeling.
"And it is so huge for me to be able to see a pair of trousers left lying on the floor at my partner's house and to step over them and not feel it is my job to do something about it!"