Need opinions please.. She sent masturbating videos

Dating for 2 1/2 years I'm in California she is in Nevada. Had a few breakups she has major issues with me and my ex wife being compatible we have kids. In March of 2017 we had a short breakup like a week. We were talking and texting the next day after the break up mostly still Arguing which turned to when I was going to drive to see her then got back together. I asked back then if anyone hit her up, she said a guy she worked for texted her telling her he was divorced from his wife she told him she and I broke up. She told me that was it. Fast forward to January 2018, I'm on her computer looking for a certain pic of us and find a video sent by this guy, he was jacking off full cum shot etc...you get it. In the same file was videos of her doing the same thing with a dildo etc...obviously sent to him. Called her out she lied saying he or she didn't send anything which then went to He sent video then She did but she didn't remember what she sent etc... She said this happened over a TWO day period during the "break up" Which wasn't really a break up.. I'm petty messed up over all this as doesn't go down that way theses days does it? I asked if they slept together she said no and had stuck to that for two months... Not sure i believe that at all... He is a total freak as she is too, so I'm not convinced. I feel she is still lying so Im about to break it off... Any thoughts? Opinions. Oh and then she tells me just the other day that the videos that were sent were some of the ones shade and sent to me... . She said she did not make them specifically for him.. What do you think I should do? She also was sexting him for that time as well, I told her I saw conversation, she said it was non stop for the two days...advice?