Several years after directing "Funny About Love", director Leonard Nimoy admitted that making this movie was a mistake, and put the blame on the script. To a degree, Nimoy was correct. The writing found in this movie is truly bizarre at times. Throughout, characters spout out deranged dialogue that no human being with a reasonable amount of intelligence would say. Also, big chunks of time seem to be missing. For example, when Wilder's character and his wife have their first argument, in the next scene she is packing her bags and planning divorce - huh? I don't know if that's how it was written, or if the editing removed some scenes, but the movie is missing important information.
While most of the blame is with the script (and possibly with the editing), Nimoy has to share some blame for the performances of his actors. More often than not, Nimoy has his cast acting in a very broad manner that makes the deranged dialogue they speak even worse-sounding.
As I indicated in the summary line, this movie is more strange than funny.