From a pamphlet on STDs for lesbians and bi-sexuals, written by the Order of Perpetual Indulgence Convent of Dunn Eideann:
Guilt
The most pernicious of all infections, you can have it for years without realising it, and the majority have it to some degree. It’s spread by letting someone else tell you what’s good for you, especially religious organisations and politicians. Symptoms include low self-esteem, feeling bad after a good time, and judgemental behaviour towards others. If left untreated, it can lead to an inability to enjoy yourself, large counselling bills, irresponsible behaviour leading to epidemics of sexually transmitted infections and, in rare cases, death through suicide. It can be treated by learning to love and respect yourself and your own values, and having a good laugh.