MMA has gotten me not chicks, rather it has gotten me many dicks. In my face. During class.
The large majority of people who hear BJJ (after the initial BLOW JOB JOB LOLOLOLOL) think tae kwon do. Only the very few who know what MMA is will care or understand. Statistically, then, don't bring it up.
Realistically, I've noticed >50% of men who go to jiu jitsu have nerdy interests outside of jiu jitsu. Likewise, I'd go so far as to bet that nerdy girls are the prime candidates for BJJ.