why do they do that? Every bleeding time? At least it's easy to spot, since they're drunk and therefore sniggering at your spiked drink before you've had a sip. I'm not condoning drug use, but it's another thing where cannabis users have the edge on drinkers. If I'm at a party and a spliff comes past and I say "no thanks" it just gets passed to the next person, no worries. But if someone, whether you know them or not, offers you a drink and you say "coke please" you get the third degree, and sometimes an indignant "I'm not buying you a coke! I'll only buy you a proper drink!" and a branding of being weird/a killjoy/whatever.