If anyone wants to get laid in life, you put the effort in. No exceptions. You know how to communicate this best to your partner, and you'll have no problem doing so, assuming outcome independence.
It's important to note the real challenge of Viking's situation
This isn't about having sex or growing old or even addressing procrastination, though they all factor in to some degree
He's experiencing a role shift, specifically going from "Lover" to "Caretaker", which is a one-way trip
As a lover you and the other share blissful moments together and you see each others attractive strengths
But once one gets sick, the other may choose to adopt the caretaker role (knowingly or unknowingly)
That role forces you to see your former, strong lover as human, fragile, and overall weak. These traits are deemed unattractive, and so you act in accordance to your new perspective.
Meanwhile, the other can still see you as attractive, and in some cases more attractive than before
No matter though since the Caretaker will never relate to the former lover as a sexual object in the same way again
This can be applied to many relationships, not just romantic ones. Parents-Children deal with this often, sometimes more than once withe everyone playing a each role at least once during a lifetime. This also helps to explain breakups and divorce proceedings where one person feels like they've cared or carried a relationship for far too long.
Anyway...
How you address it is an emotional challenge that demands high, mental fortitude
You must be strong enough to handle your thoughts and emotions, what psychology calls having a "wise-mind", to make the necessary choices that are required to keep the relationship moving forward
Not easy, but so much of Caleb's work helps men develop that mental edge so they are less phased by these challenges, and our women aren't affected by us, and instead benefit from what we do to ensure the relationship is strong