What almost everyone aside from Jabba himself didn't know was that this was all part of Crumb's stage persona. Jabba first saw the mean spirited Crumb on stage at the Laf-Fart tavern in Mos Espa, and loved the way Salacious responded to a heckler in the audience. It was only after Jabba hired him on a full time basis to cheer up all the broken and recovering people in his Palace that it became apparent that Crumb was completely unlike the character in the club.
Salacious suffered from severe moodswings and would fight with depression until the end of his days. He vomited before and after every single performance, even when he didn't eat for days. He would go for over a year without a drop, and suddenly binge drink so hard that Ephant Mon would had suffered alcohol poisoning. Deep down, Salacious completely loathed himself. The reason for this, as well as the inspiration for his stage person, was his father, Eronious Crumb. It was the same old story, and Salacious hated himself for hating his dad.
On the day Luke Skywalker came to the Palace, Salacious vomited, brushed his teeth, then vomited again before stepping out into the main audience chamber. No one was even paying attention to him anymore. Salacious tried to make people laugh, but he was completely sickened by himself. The only joy he received all day was admiring the supple curves on Princess Leia. She was easily in the top three sexiest terrorists he'd ever touched.