Do you have any particular reason to doubt your partners trust? Or is it really just about the woman? Do you think he would take anything offered on a plate? If not and you trust HIM implicity, then do as B00 says.
You could sit down with your partner and explain your fears, reassurance should come from him, maybe arrange that he phones you every evening and talk each other to sleep or something (any compromise you can reach really that makes you feel assured). Of course any woman might try it on with your partner but you have to trust him to not respond. You can�t control the actions of either person, so you may have to accept that she will flirt with him. The issue is whether you are secure enough with him. This would go for many situations at home or away.
Communicate your feelings in a relaxed way (non-accusing) without resorting to obtuse tactics (shouting, crying, threats etc).