Who should turn out the light?

Here is the setup: Partner A goes to bed first. Partner A goes to the bedroom, turns on the overhead light with the switch by the door, gets into bed, and turns on the bedside lamp. Partner B arrives, walks through the door, and gets in bed. Now Partners A and B are both in bed, with the overhead light on. Who should get up and turn off the light?

Partner A argues that Partner B should turn off the light, because they should have done so when they passed by the light switch on the way into to bedroom. On the occasions that Partner A goes to bed last, Partner A makes a special effort to turn off the overhead light before getting into bed.

Partner B does not consider it the job of the last person to bed to turn off the overhead light. Partner B argues instead that they are both equally in the same predicament (both in bed with the light still on), and so sometimes Partner A should get up, and sometimes Partner B.

Assume that due to space reasons, getting out of bed to turn the light off is a pain, which is why this is a discussion at all.

Obviously a low stakes question, but who is right, Partner A or B?