Posted by 2002p51: 
I once did a shoot with a model who brought her husband. No problem, I thought.  This was a bikini and party dress type of shoot in a public place so there would be no nudity.  The husband was constantly trying to get the model to stop showing so much skin or stop acting sexy, which was what the model and I both wanted.  He was really being a pain and she was getting both annoyed and intimidated.  After a while some guys who were fishing nearby started making cat calls and comments about this "hot babe" and that sort of stuff.  The model was completely ignoring them, as was I, and they were no problem at all . . . except for the husband.  Pretty soon he wanted to fight them all.  Needless to say that was the end of the shoot. 
I always insist that a model bring a trusted escort, but no husband of bf.

I had the exact opposite happen!  A husband who held the reflector for me, and encouraged his wife to get sexy! LOL

Posted by SindelChaos: 
Now, I will agree in some cases, that bringing your spouse or significant other to a shoot is a bad idea. 

My boyfriend, on the other hand, is very cool.  He sits there on his laptop and if he has any suggestions or has any questions, he will kindly ask and then go back to his work.  If the photographer or I need some help with setting things up or moving them, he helps.  If I'm uncomfortable, I let it be known, and if I'm having any problems with the photographer, my boyfriend will help gather my things and we will leave.  I'm totally comfortable at the shoot with him there.