I was walking along a fourth floor corridor in a building complex at the university where I work.  I was running back and forth, like I usually am, between my office building and someplace else-probably the lab.  After doing this for some time, my legs began to give way in the classic manner.  I was struggling up a short flight of stairs when I saw Jean Longmire.  I told her about some trouble I was having with a tape recorder -- the take-up reel sticking -- and apparently was referring to my legs as well.  I was heartened when she said she had the same trouble, and she showed me her tape recorder .  She said she thought she knew how to fix it.  She went into a small closet or storage room and began going through some slides and looking at them.  I stood in the doorway, and casually put my hand on her butt-just to see how she would react, I think.  She didn't do anything, but I was startled by a voice to my left.  It was Sue Hoover.  She was just asking Jean a question, but I was embarrassed that she had seen me putting my hand on Jean's rear end.