Should my husband allow me access to his passwords for email/facebook accounts?

[katsteevenz]

My husband has deceived me and lied to me and snuck around behind my back multiple times in the past 2 years. We have been attending marriage counseling which he was gun-ho about until our therapist started telling him he was very wrong for certain things, i.e. sending our private i.m. conversations to his mom and emailing her details about our arguments, inviting her to our house during an argument to be a mediator. He has taken very private info to his friends as well and during my pregnancy a year ago I read through an i.m. history on our comp where he was telling his friend that it's good that he's working out because he might be on the market again. he is the step-father to my two children from a previous marriage and the father to my now one-year-old. just recently i found out that he did cocaine on a buddy trip that he took to las vegas for his birthday, with his friends, not his wife (his second las vegas trip in 6 months without me). our marriage counselor thinks if he has nothing to hide then he should allow me access to his passwords but that i should exhibit self-control by not trolling through his private business all the time. she says it creates a security where MUCH is lacking right now. i would like to save the marriage but i can't help but feel like he is constantly hiding things from me and lying to me. just last night i asked him if he's been looking at porn (our counselor thinks he has a slight addiction to it) and he said no. flat out - NO. then i said, are you sure? a moment later and he sat quiet for a second and said, maybe a little. the first three years of our relationship i had total access to his accounts and NEVER got into them but began snooping when at 6 months pregnant he pulled away and began staying out all night with his buddies drinking and telling me i was too clingy and that he needed space. i have no trust remaining but feel like if i had access to his accounts it would provide me with peace of mind. what do you think? again, our counselor thinks if he has nothing to hide that he should offer them up but that i shouldn't be checking them all the time to allow him his privacy. she also thinks he's trying to live a single life with all his single buddies and that the pregnancy has made him regress and that he's having an almost mid-life crisis @ 30.
sorry for the novel, but HELP!