Oh nothing.....
I just get a bit worried when I see people that tensed up the moment I leave the flightdeck, thats all! Strapped in, headset on, hands on the controls...
Looks like they know something I do not at that moment and it makes it more difficult to control "ye old prostate" when in the lav...
Besides that, usually when you ask people why they do that, they tell me" in case of emergency descent, I am all prepared". Q: what is the first thing you do when in emergency descent? A: exactly...you put on your O2 mask and for that you have to take of your headset...!
just my point of view of course...