My wife is not into straight metal, but she has gotten heavily into some of my music. She loves and has gone to see both Alice Cooper and Pretty Boy Floyd with me, and we are seeing Andrew WK in June. She also went to see KISS with me in 2010.
We have a 16-month-old son, and I listen to music with him when we are hanging out, but I prefer to listen to things like Neil Young or Springsteen with him.
Also, I've posted this elsewhere before, but my tastes changes a lot after he was born. Things like Deicide and Carcass just had no place in a world where this little guy would wake up smiling at me. Definitely a persepctive changer, to say the least. Of course I still like metal, but am just less interested in listening to certain stuff.