"Upon my soul it is," -- was his answer, with a warmth which brought all the former Willoughby to her remembrance, and in spite of herself made her think him sincere.

No surprise I hope but yes, this is a post about Willoughby’s lies in Ch. 44. I do believe Willoughby is a dishonest person. Here are five instances where Willoughby seems to be lying:

Is Willoughby lying about being very drunk? In the past it has been suggested that he is joking rather than lying. What is supposed to be so funny?

Did Willoughby not know Eliza would be “reduced to the extremist indigence” after he left her on her own? I cannot imagine Eliza became his lover but kept her financial circumstances a secret.

Did Willoughby forget to give Eliza his address? It strains reason in my opinion. Surely he failed to provide his address because he did not wish to be found. Eliza told Col Brandon he promised to return. The lie probably let Willoughby argue she would not need to write.

"I do not know what I told her," he replied, impatiently; "less than was due to the past, beyond a doubt, and in all likelihood much more than was justified by the future. I cannot think of it -- it won't do.

Does Willoughby really not remember if he told Marianne he would return to Barton? When Elinor asks his answer (above) suggests an awareness that he did. In Ch. 16 Marianne believes he will return in a few weeks.

Did Sophia compose the dreadful letter Marianne received from Willoughby? The way he spoke of Eliza and Sophia convinces me he is quite capable of composing the letter, especially with Sophia looking over his shoulder.