I dunno... Jen, my fiancee, and I have both been involved in various arts throughout our lives. Me in TKD and Kendo, her in Tai Chi. So we both enjoy it. But we both agreed it would be better not to take TKD together, since I got her excited about it. It's okay to train together now and again, but she and I both don't think we'll be able to give or take commands from each other in class together. We're just... well, goofy when we're together, and that doesn't work well in a martial arts class. The other side of it is that, unfortunately, my sparring style usually contrasts the difference between my high pain tolerance and my opponent's lack thereof. In other words, it ain't always fun to spar me, and she didn't wanna unless it's no contact, which I do outside of class. In my class I can and will be happy to go easy on students who aren't up to my level, but I prefer to go as close to all out as I can with those who CAN keep up, and I don't like the idea of fighting Jen in that state. I'm not entirely someone I like when I'm in fighting mode.
But mainly, we just didn't want to have to stifle our inside jokes when I'm in front of the class.