It's the same with any sport, in terms of sexual connotation, etc. Recently with the growing popularity of "no-gi" Brazilian Jiu-Jitsu, the practice of giving out belts to no gi practitioners e. I think folks should just be casually out about it. Tonight for example, a blue belt asked about which city my wife liked best from our recent trip. It's only gay if you make eye contact - Ridiculously
Unless someone is really trying to be pervy, then there's not a whole lot of time to worry about the "intimate nature" of BJJ.
Like Steph said, a lot of times people will apologize to me for grabbing something and I'll have no idea what they are talking about because I was in the heat of the grapple. No problem OH! A gay guy who is trying not to appear gay would not say something like. This website is about Brazilian jiu jitsu BJJ.
The kind of attitude I'm familiar with is exemplified by my favourite martial arts forum, Bullshido.