I Can't Say No.

I had always considered myself happily married and straight.
Then a drunken encounter with a long time male friend ended with us watching porn and masturbating together.
The next day he phoned me to say how exciting it had been and asked if I was available to meet him in a motel.
We met a couple of days later in a motel and he put some porn on his laptop but this time it was bi males not only having sex with women, but sucking one another off.
He commented that it looked like fun and then asked me if I'd like to try. I was already horny but agreed to let him suck me. He gave me a suck for a few minutes and then asked me to return the favour. I wasn't keen but said I'd do it anyway.
I was amazed at how much I liked sucking his cock.
We have since met several times and it's now led to anal. I love his cock inside me and when ever he phones I always try to say no....but I can't. I can't stop thinking about his cock and how it tastes and how amazing it feels inside me.
My wife would be furious as would his ...and I know it's risky but I can't say no.
I need his cock so bad.
Even now typing this I just want to suck him!