after recently discovering that i have a 'tickling fetish' (i get very turned on whenever i tickle my boyfriend in bed, and had THOUGHTS about tying him down while tickling him)... i was told that this tickling fetish is actually quite a common thing among BDSM circles, since tickling is considered to be a light form of torture. Is this true?

I'm really surprised at this, since i've never considered myself being a BDSM, and I know my bf is definitely NOT into the scene. Anyways, other questions i have include bondage: what's considered "light bondage"? and for anal sex... not sure if this is fact or fiction but do only BDSMs practice anal sex?