Besides Dr. Jekyll, what characters throughout the novel "conceal their pleasures" and what are the descriptions? Why do people "hide" their desires?

I'm not sure there are any stated hiding of desires of characters other than Dr. Jekyll. I suppose all of Victorian society did this to some extent. The Victorian world was very sexually repressive. There are critics who speculate that the character of Utterson might be a homosexual but that is an interpretation. We all have primal desires that we hide. We are mammals after all but we follow a social code.