"Some couples cope with this sneaky primitive mechanism by cranking up the dopamine using porn or acting out sexual fantasies with their partners. In both cases, they attempt to fool the brain that a new mating opportunity has arrived. Others raise their dopamine by artificially generating intense feelings (as with bondage), or swapping mates. However, it can be exhausting to have to orchestrate a dopamine surge every time you want to make love. And what happens when one partner wants a "fix" of sexual excitement and the other is not ready to invest so much effort, or run the proposed risk, to get a thrill?"
What If She Were Always in the Mood? | Psychology Today