It is said that you're supposed to share everything with your partner. The good, the bad, and even the ugly. But of course, some people don't follow suit. 

I mean, that's just a disaster waiting to happen because in case the secret does come out, it ends up hurting a lot of people. And, that's not just me saying it, we found a Quora thread of people who shared what their partners had hidden from them and how exactly they found out about it. 

1. "When I met my husband, I was told he had slept with his sister-in-law. On being confronted, he said it only just this one time but when my sister-in-law was on her death-bed, she called to inform me that it had happened more than once and my husband stopped her from telling me because if I knew the whole truth, I wouldn't have married him. It was and still is my most painful experience in life." - Rebel Redford

2. "I overheard my wife telling her friend that she has had bigger dicks than mine and that it would be nice to go back and experience it once again." -  Anonymous

3. "My co-worker claimed to know something disturbing about my present partner from his ex. While discussing the same with my partner, we got into an argument. He revealed that when he was 12, he had sex with his dog using a condom he found on the road. That's how he lost his virginity. His parents then forced him to tell his siblings that he raped their dog." - Anonymous

3. The doctor advised us to walk 1,000 steps every day so our son gifted us an activity tracker. I couldn't accompany my husband for walks due to my acute knee pain. But my husband kept walking the required number of steps and sometimes even more. One day, he walked significantly more and came to show me. But when he looked at his wrist, the watch wasn't there and he went out to look for it. During that time, a young boy rang the bell and returned me the same watch saying that my husband forgot to take it from him today. Puzzled, I enquired more and that's when he revealed my husband asks him to wear his watch while he jogs. And, when he does that, my husband sits with his friends. -  Vijaya Lakshmi

4. "I found out that my boyfriend of 6 years was cheating on me with my sister when I read his text on her phone saying 'I hope you had those contraceptive pills.' When I asked my sister about it, she just stood there quietly. Her silence told me everything. The love of my life cheated on me with my sister.  My own sister did this to me." -  Hanna Wati

5. "My father had Parkinson's so I let him move in with me and my wife without discussing it with her. After a while, she abruptly left without any trace. I had to ping her family for an entire week to contact her. When we finally met, she told me that she had gotten a new apartment. I was shocked because I didn't think she would be this upset. Later on, I moved in with her and let my dad stay in our old house. When the lease of our new apartment got over, we moved back. 2 years later, she slips out during a conversation that the couch I was sitting on, was bought by her boss when they slept together the first time. It was because of him she moved out and not because of my father. " - Scott Pierce

6. "While surfing PornHub, I looked up at the trending videos section and found my girlfriend there. Turns out, she was doing porn films for 2 years. I wasn't insecure or ashamed. Just thought that's something I should have been told upfront." - Rey Horton

7. "My boyfriend wouldn't stop liking and commenting on this lady’s pictures and tweets on Twitter. I asked him who she was but he denied having anything to do with her. Later on, I saw her post his picture. I followed and asked her about him. Turns out, they had dated even before I had met him. My boyfriend stopped picking up my calls for about a week. He, then, replied with a picture of him in the hospital saying he got his karma." - Juliet Joel

8. "I was at the restaurant with my cousin when my boyfriend showed up with a girl. I didn't do anything impulsive. After they were done, I walked up to the girl and told her that she was lucky to be with a pretty guy like him, just to get information. She laughed and mentioned that she has been with him for 2 years and loves him. The next day when he returned to me, I had already left by then and wrote him a savage letter on his wall using permanent paint." - Dana Hilton

9. "The secret was that she was having an affair with an illegal immigrant from El Salvador. What gave it away was the fact she got pregnant as a result." -  Daniel Metivier

10. "That she was fucking my best friend! I followed up on her one night and discovered her jacket in my best friend’s car. Shortly thereafter I caught them in bed together. Pretty cut and dry." - Kris Nystrom

11. "My second wife kept it a secret that she had been sexually active with women prior to our marriage and that she was either bi or gay." -  Louis Lombardo Jr

12. "My wife was having a fling with a family friend. After a few weeks, I realised that she was not having her period. She went into panic mode after I commented that she was bloating as well." - Lurch Edward 

13. "My first wife was a nicotine addict and I never got to know until we got married. I’m very allergic to cigar smell and I throw up anytime I inhale it. Throughout our courtship, she was always chewing nicotine gum (which I didn’t know about). After we got married, I caught her smoking but I didn’t get mad because I thought she was just an average smoker. After asking her why she hid it from me, she said she never got the chance to smoke around me while dating. Days went by and I realised she smokes more than a pack of cigars daily. It was uncomfortable for me and became the bedrock of almost all our problems and we eventually had to separate. - Nicolas Hana

14. "I found out after our divorce that my wife had purchased a home in another state and I never knew of it." - Henry Hriczko

Well, the truth eventually comes out no matter what you do. 

Comments have been edited for clarity.