I was speaking to a friend a few weeks ago and she referred to her husband as "DH" using that exact term. I smiled and asked what she meant and she said "Oh, sorry I meant my husband" I automatically knew she was therefore a MNetter.
I've adopted saying to friends to burn down their house should they find a spider but I'd love to know what gave away your MNetter friends? I think it also feeds into the idiotic (if I may make so bold) suggestions that NChangers feel when they NC - just get on with it i.e 'Penis beaker' 'T-rex in Asda' or whatever.