I'm so very sorry you've had to find this out. It must be devastating seeing as you now probably feel piggy in the middle. Obviously you have to do whatever you feel is best. But if you put yourself in your mums shoes would you want to know? How would you feel if you knew your daughter knew but didn't say anything? 

Personally if it was me I'd have to confront my dad and tell him I knew and ask him to tell your mum (his wife) and give him a period of time to do that, say within a fortnight and then say you'll have no choice but to tell her yourself. 

Sadly I have had to do this and tell a friend. We met for lunch and I told her in a coffee shop so it was in a neutral space. Of course she was devastated but thanked me for being a friend. I felt absolutely terrible watching her relationship break up but i knew I couldn't hide it from her. 

I hope you find the strength to do what's right for you and your family right now. 

Hi if I were you I'd be asking myself what I would gain from it ,or your Father or Mother ,if it was me I wouldn't say a thing especially with your Father being so ill and it would be really upsetting for your Mother ,it would be one of those things I took to the grave with me because it won't benefit anyone at any time ,so sorry to hear about your Fathers state of health .

Thank you to both of you for replying. I feel devastated. My dad is in his early 70s and he was diagnosed with pancreatic cancer last summer. He had attempted surgery in December to remove but it was unsuccessful. He ended up in intensive care and nearly died. It was then that I first discovered the infidelity. My father is always very protective of his phone, especially around my mum, but whilst in the hospital, we needed access to see if his sister had been in contact. (She is estranged and none of us have her details). So I got into this phone whilst he was in ICU, and we saw had been in contact. But I also saw underneath her message, a conversation with another person. It was an unknown number.

This was a conversation where my dad was saying he wanted to see the person again. It shocked me and it was clearly an affair of sorts. I deleted the messages and number. I told no one and shut it out of my mind. Dad's recovery from surgery was long and slow. It's been gruelling. My mum is incredible. With dad so unwell I pushed the infidelity to the back of my mind.

He is having chemo and the tumour is growing but slowly. Dad is one of the few where it is slow, giving dad more time. Docs don't know how long he has, so we're doing the best we can as a family. 

With dad so ill, I was able to push those texts out of mind. He has been too ill to go out much. Dad rarely goes out on his own. He has recently visited his brother in London (2 hour drive) on his own, on two separate occasions. We were all so worried about him driving on his own. As he is not well. 

Last week, dad was asking for help with an app. I checked his phone and saw more messages to someone else, to a contact he had saved under the guise of "Cricket Club" - Deceitfully done. His messages were "i want to see you again", "when are you available?". They were messages with a s*x worker that included prices and a menu of acts. There was an address. Using his Google Maps, I looked at his timelines. It turned out he stopped off at this address for 1.5 hours en route to his brother's on the most recent occasion. I am so gutted. So disappointed in him. Dad isn't very good with his phone. He won't even know about timelines.

I feel crushed under this burden. I don't know what to do. My mum has given up her life. When she pops to Sainsbury's she hurries back because she worries about my dad. She won't go out for lunch with friends. I've told her recently to do things for herself. She says: "You don't understand, I can't leave dad alone for long. He's dying." She says he doesn't have the energy to even make a cup of tea for himself. My mum does everything for him. She is sacrificing so much. My father has the energy to visit s*x workers.

I took photos of the Google maps and the texts with my own phone and I deleted the messages and the "Cricket Club" number from his phone. I'm hoping this will make him realise someone knows what he's been up to.

I feel like I have to take this to my grave, that I will now forever be disappointed in my father. How could he do this to my mum? It's revolting. I am shocked, saddened. I can't hug him. I can't even look at him. I am trying to be normal around him, but I feel sick with disappointment. :-(

Hi ,this puts a whole new light on it you must be devastated I know I would be ,its a terrible situation and now you know you can't unknow ,I know what it looks like and really I know there's no other explanation than he was visiting a sex worker it just seems so bizarre for someone so ill to be doing this ,I suspect he's on lots of medication could this not somehow have affected his mind and judgement ,I've heard of really ill people on lots of medication affecting the brain but I don't know ,my thoughts are with you and your mam and its a real dilemma how to handle this for the best outcome ,I think your mam needs protecting from this because it sounds like it would break her probably even more than its done to you ,Its absolutely heart breaking there are no easy answers ,sounds like you need some real support to get through this ,at least stay on here as its good to be able to have a chat and maybe others will come on and give their advice ,my heart goes out to the whole family x