I had a lot of this at school when I got into Trek back in the 90's, but I was bullied even before I got into Trek. If you were a Sci-Fi fan in the late 80's/early 90's you were toast!
The annoying thing I found was that when I was into Trek I got told by everyone how "crap" it was, but then a couple of years later, some of those people were coming to me saying. "Did you see that Star Trek episode last night? It was great!"
...hmm, can you say hypocrites
My friend and I were talking about the terms "geek" and "nerd", he found them to be offensive, but I say EVERYONE is a nerd or geek.
Everyone finds something that they can become healthily obsessed with, whether it be a TV show, a comic, a novel series, sport, football, basket ball, tennis...etc.
We have a great fantasy writer here in the UK called Terry Pratchett and he said in an interview, that he always thought it odd that someone who had [insert sports team here] shirts, bedsheets, alarm clock, curtains, posters etc. was considered to be perfectly normal. While folks who put on a pair of Spock ears and went to a Star Trek convention were considered to be a little weird.
I say, see their weird look and raise them a Spock's eyebrow!
To cross Trek with poker!