to do a 'pybus' is to touch a young women, without their consent, and against their will, women are usually still in their teens and are by law, protected virgins.
Adam: My sister got pybus'd last night.
Dan: Why? I thought she was a teenvirgin.
Adam: She WAS!
1. when you have just dumped or been dumped, and you are feeling majorly low, and all you wanna do is sit around and cry and eat chocolates and strangle the teddy bear he gave you...
2. if you've just been parted from something you majorly love, and you're really down about it.
"dude...i'm suffering from PBUS"
"damn it! i can't believe i'm not the play is over, i'm having theatre PBUS!"