What to do?

I am strongly attracted to a close friend of my wife, and I am getting messed up and confused.

My wife's friend - lets call her Annie - is a sweet beautiful woman and we all get along really well. One night we were having a dinner party and the other guests slowly went back home one at a time or in couples, eventually leaving my wife, Lola, me and Annie. We were all a bit drunk and Lola and I have talked openly about how beautiful and fun Annie is. I started to get this vibe, like someone does when they fancy you, long looks and heavy words, and I'm starting to get a bit turned on, so I try and go with it.

now Lola and I have had threesomes before, it was something that we talked about and did before we were married. We would go to bars and pick up cute chicks and take them home and have a wild night. We have some rules that make it safe, I mean emotionally safe, to avoid jealousy. One of the rules is no friends - because to us a threesome has to be a one-night-stand. You aren't starting a relationship with this other person - they are a sex toy - and they have to realise that before hand.

So how can you do that to a friend, right? Use them and leave them and try to not have that effect your friendship.

Right - but I was getting this feeling, from Annie and Lola, that this was going to go somewhere. But it didn't. After an hour or two of drinking and chatting and innuendo, Annie said that she was tired and that she should go home, and she did.

So that night I asked Lola what had happened - were we heading for a threesome with Annie.

Lola said that we weren't. That Annie was cute and all, but we couldn't do that to a friend.

I agreed, but there was something so enticing about her.

I have started to become obsessed. I think about Annie all the time, I look for porn pics of girls that look like her. When we visit her I come away feeling frustrated and confused, like I did in high school when I fancied a girl and didn't have the guts to say anything to her.

What do I do? This is quickly becoming a problem. I think that I am suffering from the old "want what you aren't allowed" human condition.

I'm lost and adrift.

Any advice?