if it makes you feel better, that kind of thing doesn't just happen to new cyclists, or to women cyclists. i've been made fun of, my boyfriend has been made fun of, and what it boils down to is that some people are just mean. it's a shame that they bring their negative energy to a group ride. it's clear to me that they were just intimidated by a new face. if they were really confident as cyclists, they would encourage and welcome the new person. so, no worries for you. good times ahead!!