Then there was the Mad Russian, who made her laugh and behaved impossibly badly and proposed to her daily. Some other shorter-lived liaisons, now forgotten. Then Henry.
— William Nicholson, Secret Intensity Of Everyday Life
In the context, the narrator says the word liaison without rendering any moral viewpoint. Though many dictionaries contain moral defects in the word, Longman Advanced American Dictionary says liaison means “a sexual relationship between two people who are not married” without any further moral angles, and Merriam-Webster says it means “a close bond or connection”.
Can we use the word liaison casually, like in the example?