jaquta is right.You have to deal with the source of your mistrust.is your boyfriend known to be untrustworthy in this area?do you have a history of being betrayed?are you insecure or plagued by self-doubts and worry that you are not good enough for your boyfriend? These are the kind of things you need to work on. You can get some help directly from a therapist or you can go to my site my virtual shrink.com and begin to work on these issues online.