First of all her lie about not having sex with the guy she was dating before you sucks, it was a lie but it was a fairly innocuous one maybe she just didn't want to admit to having sex so soon before you .

That was my first thought, that she might have been...embarrassed(?) to admit how recently she'd had sex. Not that I would have cared, or would have had any right to, about what she did before we met.

Second of all I think she cheated on you on that cruise, this guys messages hint very strongly that they had sex. The fact she never told you this guy was her prev lover is a huge red flag.

That is my absolute biggest fear in this whole boondoggle. But I don't know. I read once that in situations like this, one has to realize that a good person can do bad things, and I do believe that she is a good person at heart, so it's more important to focus on the specific bad thing (the omission of their relationship) than to demonize the person outright. That's what's keeping me fucking sane right now, anyway.

They even had a conversation shortly before we met about her maybe trying to set him up on a date with a friend, and her lamenting to him how she couldn't find anyone she connected with in our area. Other than the specific messages I cited, there hasn't been anything flirtatious between them for a long time. That lends me the slightest bit of hope.

I don't know how to handle it when I do ask her. Like, if she swears up and down that nothing happened...how do I take that at face value if she's willing to lie about little things like the sex before we met, y'know?

Thirdly you need to talk her tomorrow. No you cannot talk to her on her husbands anniversary but you also cannot wait, so call her up and tell her you and her need to talk face to face and you know she lied. Ask if she can come to you or you go to her and thrash this out tomorrow, waiting another week will not serve you.

I could probably make it out to her tomorrow (we live a few hours apart, but she's close to my university so I spend several nights each week over there, and every weekend so far).

My biggest problem is how to open the dialogue. I really want to make it a discussion, rather than trying to be overtly accusatory, but I don't know how to broach the subject without seeming accusatory.

Also you were right to look through her phone so stop beating yourself up about it. She needs to stop lying to you about her exes and you need to look her in the eye and ask if she cheated on that cruise.

Thank you for not demonizing me for looking through her phone. I knew how most people would react to that admission.

And like fuck was she celibate for 4 years

The optimist in me wants to believe that, in particular. Like I said above, I still feel like she's a good person at heart (a feeling that I very much did not have when this happened to me before), and it would take a special sort of monster to cheat on her husband while he's fighting cancer.