(Muck, this one is for you).
I got her again!

(And almost a year to the day).
Not as bad as the first time, but plenty messy enough just the same. I noticed the return line needed a good cleaning again, so after some lengthy negotiating I convinced her that it would work better this time. I disconnected the return line from the pump and had her hold the ball valve in her left hand, facing away from her. When I yelled "OK" she was to open the valve with her right hand and the crap would blow out away from her. I turned on the compressor, waited a second and yelled OK. I heard a shriek and ran around the corner to see what had happened. Sure enough, she was covered in crud again! "You are an A$$Hole, and I Hate You!" she yells at me as she runs to the shower.

The pressure had broken the glue seal and blown the flex hose right out of the ball valve. So she's standing there with a ball valve in her hand while the flex hose is spraying goop all over the place. Needless to say, she doesn't think it was very funny this time. Now I have some major sucking-up to do. This might cost me big time: a trip, or at least some jewelry; I don't think flowers will do it.
P.S. For those of you who don't know WTH I'm talking about, see the beginning of this thread.