That does sound tough to deal with.. sigh. My only guess as to why they give the "why not" reaction and run with it, is because they're scared. As humans, we often fear that which we do not understand. As happy drug users, they can't fathom why you wouldn't want a piece of that "happiness" or "peace" they get when they're high. That lack of understanding (due to time and other factors) gets translated into fear. Fear translates as ending the conversation or something similar, which results in you feeling the way you do.

Identifying the problem isn't necessarily the hard part though. How can you solve this? I'm not too sure to be honest. Perhaps associate with other friends? Come up with witty comebacks or phrases to just unload on people when they start acting a certain way because you refused drugs? It's tough.

Personally I don't drink. When people call me out on it, I usually just tell them I had an operation that basically doesn't allow my body to react well with alcohol anymore. That usually shuts people up lol