Fiance slept with a prostitute

If we give him the benefit of the doubt and say OK, his friend took him there, it wasn't his idea but I still have questions 1) If he was that drunk how did he manage an erection 2) why would he agree to the sex then stop after 30 seconds 3) why would he tell you all this unless he thought you'd find out ie will his friend turn up and say you still owe me money for the sex at the brothel.
It sounds like one big, big string of excuses to me Op more likely his friend talked him into it and he got the fear after

Said he started freaking out saying wtf are you doing this isn’t right etc. <<< if he freaked out he wouldn’t have even be able to get hard.

Then he said no I can’t do this and ran out of the house and made his way home <<< YEAH RIGHT

he said the above to make it seem like he wasn’t okay with it but fact is he wouldn’t have been able to get hard, and he didn’t have to f her, could have went in the room and pretended to his friends if he felt under pressure

he’s crying because of guilt and to release his guilt. Up to you if you give him another chance but from my experience men who cheat always end up doing it again if you stay.

The story he’s spun you of how this came about will not be true, the truth will be so much worse.

I do apologise, my post was rather crass!
Allow me to rephrase my thoughts on this matter.
Broadly speaking paying for sex doesn't work for women in the way that it does for men. Furthermore it's generally not too difficult for women to find a man who is willing to have sex with them on a casual basis, even if she's not much of a looker and he's hot stuff.
If a man who is an average fat bloke wants to have sex with an attractive woman he will need to sweeten the deal with some money.

Yes, this is what stood out to me as well, OP.

How does he explain that?

I would hazard a guess, of all of the mistakes the members of Mumsnet could make, accidentally having sex with a prostitute is one of the most unlikely.
It wasn’t even a mistake, it was a decision to cheat.
I hope you raise your own standards.

Its interesting that he a. Timed it b. Was too drunk to realise what he was doing but sober enough to time his mistake c. Thinks 30 seconds is better than 30 minutes

He accidentally had sex with a prostitute?…Seriously OP stop being a doormat.
that’s the most absurd story ever. Dump and run..if he can con you into believing this level of bullshit then can you imagine what your future will be like? It will be one con after another until you’re exhausted and your ability to trust your own instincts and other people is shattered. He’s not a good person.

Get rid. This piece of work has shown you who he is. He WILL do it again, and again and again. Don't believe his lies.

Nothing about that story rings true. Sorry.

Am I being really naive to forgive him?

So naive I can’t even tell you. He’s told you a version of this that is likely so far from the truth, it’s unrecognisable. He’s tried to make it palatable to you, while still being ‘honest’. He’s not being honest. You’ve been given a warped version whereby he’s tried to paint himself almost as a victim.

You’d be an utter fool to believe that and even more so to marry him now. He’s blown it.

Weirdly, I’ve accidentally been on a brothel. Different country, looked like a bar. Oops, I made a mistake. Told DH, he thought it was hilarious.

There’s a long way, full of conscious decisions, between that and having sex with a prostitute. Not ‘mistakes’, conscious decisions. If someone went for my DH's belt buckle unwanted, I could hear the “WTF” from space. Men aren’t stupid puppets, who need to be protected from their idiotic ‘mistakes’. A man has sex with a prostitute, he deserves any consequences he gets.

Apart from all of that, he had no idea if she was coerced, pimped, addicted, desperate. What he did could be (and is in my mind) rape as well. Sex with money isn’t full and enthusiastic consent, and is worse than typical cheating.

Please don’t marry this lying sack of shit. Also, please get yourself tested.

That would be ex for me.

This exactly. He's either a lying little shit or someone with so little backbone that you will have to police him for the whole of your married life.

Not so paralytic that he couldn’t walk, recognise that he wasn’t in a workplace, and he still managed to get an erection?!?!? He’s a fucking liar!!!!!! Walk away, keep walking and don’t look back…….you deserve better.

So sorry this has happened to you. First things first take some time to think about you, how you are feeling now, how you will likely feel in the future.
secondly and I say this not to worry you but do go and get a full sexual health check. This may or may not be the first time this type of behaviour has occurred. Lastly try not to attribute any of the shame yourself. This says nothing about you and is no reflection of your morals etc. Do not go through with the wedding just because you’re embarrassed and don’t want to let people down etc- you haven’t caused this your partner has.

You know whats worse than the cheating?

The BS he's peddling.

He drunkenly thought he was meeting a business colleague? He didnt recognise a brothel? As his pal negotiated the price/paid he stood there?

Then instead of leaving, while he was stood there "freaking out" protesting and saying it wasnt right you believe this woman undid his trousers against his will?

AND HE WAS ALREADY HARD!?

He just stood there confused as the condom was put on? And what slipped and fell inside her? Like accidently?

That isnt what happened. Why would a colleague pay for a prostitute for him against his will. Didnt happen. Hes not a victim in this.

At best Id believe he willing went, if not knowingly, and half way through regretted what he was doing and legged it. And now feels ashamed of himself.

You might be able to forgive a lapse in judgement (not sure i would, but you love him so no judgement) but you should absolutely not forgive this fairytale that if true would be SA. Because that didnt happen hes BSing to absolve his guilt while dodging accountability. You cant trust this selfish man.

he has done it more than once… he’s done it many times

It’s all someone else’s fault isn’t it? His friend, the girl, everyone but him. And that’s if you believe his story. Which I don’t.

Agreed. His version makes it sound like he was practically almost sexually assaulted…

It sounds too like you want to still get married if you can be assured was a drunken one off… no one can give you a cast iron guarantee though. You’re invested, wedding pending and not wanting to tell anyone in RL, sounds like you’ve already decided to forgive him.

Just really sorry it happened. Never ceases to amaze me how women can often (and musing just in general) fall so hard for what are when it comes down to it weak and mediocre men.

So a man who was paralytic manages to remember an event in detail and get enough of an erection that a prostitute could put a condom on and for him to have sex with her.

Ok then…

He is telling you this before someone else tells you what actually happened. Sorry.

It would be completely reasonable to break up with him. But I am going to put out what will be a completely unpopular opinion and say that of all the cheating scenarios I've come across, the fact that you think he genuinely has strong morals, and he (according to him) was unable to go through with it, told you everything without being caught out, and felt awful, does make it possible that this has taught him he never wants to cheat again. So while often its "once a cheater, always a cheater", if you really want to give it another go, and really believe he is a decent person and won't do it again, it may not be completely foolish to stay, as long as he is willing to do whatever it takes to earn back your trust.

This makes no sense. Why would his workmate take him to a prostitutes house randomly? He wanted to go there.

He may be regretting it now But the decision of what to do now is yours. I’m so sorry. What an awful shock

Could you be "convinced" into using a sex worker? I couldn't.