"Contrary to what has been widely believed, long-term romantic love (with intensity, sexual interest, and engagement, but without the obsessive element common in new relationships), appears to be a real phenomenon that may be enhancing to individuals’ lives—positively associated with marital satisfaction, mental health, and overall well-being. [...] long-term marriage does not necessarily kill the romance in one's relationship"
"Contrary to what has been widely believed, long-term romantic love (with intensity, sexual interest, and engagement, but without the obsessive element common in new relationships), appears to be a real phenomenon that may be enhancing to individuals’ lives—positively associated with marital satisfaction, mental health, and overall well-being. [...] long-term marriage does not necessarily kill the romance in one's relationship"
https://journals.sagepub.com/doi/full/10.1037/a0014226