Womanizer was written in the spring of 2011 and was an idea that Mark Sinacori had since he and others around his twenty-something age he had been around had been clubbing on and off and mostly had been around older women who seemed easier to get with than with the girls their own age who were more selective on who they went out with. Some of these guys would lie about their age to make them seem older than they really were or flaunt their jobs as being high up and some of the women would buy this, something that had been an ongoing thing he'd observed with a lot of guys his age. That's how half of the story of Womanizer came about, the other half, Mark Sinacori's own imagination and experience with watching great nighttime TV dramas.
Womanizer filmed in the summer of 2011 and was Mark Sinacori's first short film he wrote, so he took it slow. Several factors came about which caused the production to halt several times the next three years, but as with many shorts and even features, some never even see the light of day and are never completed because of lack of funding and other issues. With Womanizer, the fact that Mark didn't direct it and others on the crew wanted him to save money with the editing instead of it going to costly editors, this caused several long halts in post production due to others in post production who had personal problems come up they had to attend to which only caused further problems the following three years that halted the film to be finished, until Mark and his director of photography, Kevin Boot, had to fix any of the flaws made in the final editing themselves before Womanizer was finally completed in the fall of 2014.
John Blyth Barrymore, Drew Barrymore's older half brother, who was Mark Sinacori's acting teacher at the time in 2011 decided to direct the film after he saw the script, and to the fact that everyone persuaded Mark that he'd be too busy with handling everything else that he'd be too busy to direct and that he should find someone to direct it instead. John wanted to keep the film at fifteen minutes, which Mark didn't mind if it was a few minutes longer, and because of this, several cuts were made to the script, and two scenes that were written were entirely cut out from the finished product. First, an early scene of Casper meeting Ricardo to go to the park was cut out and went into great detail of how Casper was inexperienced with women and how Ricardo advised him to get with older women who were easier to get with and believed anything younger guys said. Second, the scene where both Casper and Ricardo meet Angela and Meredith at the car was supposed to end with Ricardo approaching a clueless Casper and giving him advice on what to do after he goes out to Norm's with Meredith, but this was also cut out of the film, and one last scene where it's later on and Angela is in her car with Ricardo and she explains her husband is out of town and she's all alone leading to them kissing was also cut out from the final product to keep it at 15 minutes in length. Because of these few cuts, Mark Sinacori's role as Casper being the tag-along clueless virgin was drastically reduced in the final product.
On the very first day of filming in 2011, Mark Sinacori had a very bad cough and realized something was wrong as it hadn't gone away for several days and was just getting worse. It turned out he had pneumonia and he was not able to be present during the filming of any of the scenes that were filmed the following several days which did not include his character of Casper. The first scene Mark filmed for Womanizer on day one of filming was the one of him on the phone as Casper talking to Ricardo. Throughout the filming of it, he had pneumonia, and was coughing during every tape stop.