Obviously the way most people get caught is by telling people they use DNMs.
Only a select few people know about my usage of the DNM usage. However, sometimes I'll be in a position to do drugs with or asked to do a drug with someone that is hard to find in my area, yet I have it.
What excuses or reasons do you give for why you always have a great hookup? Just be quiet and tell them its none of their business? Tell them you have a good dealer?
Ecuadorians. Some Polish guys. Hungarians. Mexicans. Whatever. Just name a random group of foreign descent and they shut up.