My worst bad habits right now are swearing and nail biteing.
Luckily for me i have an automatic off switch embedded in my brain so i dont cause myself or anyone else any embarressment with it, i know this is going to sound really strange but the swearing started when i stopped smoking, maybe that was my outlett, who knows.
As for the nail biteting, ive had an on going battle with it all my life, the only time i ever grew my nails was when i was pregnant, but i had to draw the line after 3, my feet and back were killing me pmsl.
If you were to ask my family about my bad habits they may have their own opinions lol but hey, we arnt perfect are we ?
Im not going to get into my hubbies bad habits, the sites not big enough lol, but if i had to pick one, its switching off and not really paying attention when im telling him something, then it riles me to repeat it later but i guess it could be worse :P