Frustrated at Forty

Back in the early 90’s, an acquaintance – a pig of a guy, that has a story for EVERYTHING – once told me that guys and girls (maybe he said chicks and dudes) can NEVER be just friends. He said that guys always are being friends just to get in the girls pants. Plain and simple. I argued several friendships that I had and he asked if I would hit-it if given the opportunity. After thought, I said that I could. He raised the stakes a bit and said if we both had a few drinks; were stuck in a hotel for the night; and the T.V. was broken and stuck on – with only porn channels on. Would I be able to control myself? I assured him that I could. He called bullshit and said that all guys just want to have their dicks sucked or to be sticking it in a girl – friends, enemies – no difference. He would always say that if you didn’t want to have sex with a girl – especially HOT ones, something was wrong with you. He will further argue that is was okay to WANT to have sex with someone, like your friends girlfriend, but ACTING upon that was totally against all dude rules.
After what happened today, I am fucked in the head. Was the blood rushing to my penis a reaction to the person that I was hugging? Was it my penis knowing something that my brain won’t admit to? Was it just a circulation issue and I should give up on it?
I truly wanted to talk to my wife about it but I don’t think that anything good would come from that conversation.  It’s not like I want to have sex with B.F. – it really has not crossed my mind.
I thought about calling B.F. again and spilling my guts. She’s my friend afterall, but would this corrupt that? I don’t know how I would feel if she told me that.  We honestly can tell eachother anything, but I don’t think I can tell her this as I don’t think I want to know what her reaction would be.
Can guys and gals be best friends with no sex involved? Can we be trusted? Is this cheating – just the fact that I had a boner from someone other than my wife?
What if she shuts me out as a friend – I can’t risk that as I need our conversations.  If she thought it meant more, I can’t handle that.  If she felt the same, I don’t think I could deal with that – I need a friend right now.