How good can they be ?

Good evening, im lost. I have been in a very rocky, complicated and i believe mentality abusive relationship for a long time now. One thing i always believed though is, he may hurt me emotionally but at least hes faithful. Hes got two phones, a work phone and a personal. I have access to both but only ever went through them at night. There had been about 2 occasions i saw messages with ramdom women, only one of them being inappropriate in the beginning of our 6 year. Anways, i honestly still believed that through all the pain, hes still been faithful. Until recently, some people have been going to my relative and telling her they have seen my spouse with a other women. They thought we had broken up. Its a small place and most people kinda know most people. Anyways, two of the individuals who said theh saw him, i am having a hard time to find reason with them lying but im also having a hard time believing my spouse has been unfaithful. There as been a couple times where my spouse as been weird when i ask to just hand me the phone ( hes showing me a vedio for example, soitry to just grab it to watch) im not really sure if theres anything else because i honestly haven't been looking. I feel so confused. How good was your cheater on hidding the evidence? How long did it take for them to get caught?