<human>: Can you succinctly summarize the text in 1-3 sentences?

So I have recently (~4 months ago) started a really brilliant relationship with a new man and up until last weekend I really thought that I couldn't be happier. I knew that my SO had just got out of a long term relationship with someone he broke up with because of extreme mental health pressure, so I've never pried too far because I understood it was a difficult time for him.

However, a casual comment recently by one of his friends led to me doubting exactly how long before our relationship started, he broke up with his previous partner (full disclosure: my SO is bi, previous partner was female, I've got gay man's guilt from dating a bi man where I'm scared he'll leave me for the societally-easier heterosexual alternative - I know it's bullshit, but it's still a worry in my head).

So the other day I looked through his phone (yes, I know, bad, ok) and found the thread of their texts. IMO it's almost definite that they were still dating at least a few days into our "official" relationship - even a couple weeks after we'd got together officially, there are text exchanges about picking possessions up from each others' houses, and language used to refer to each other in the first week or so that we were dating is pretty clearly not platonic.

I struggle with anxiety and am terrified that I've misinterpreted it all and am going to ruin this relationship if I confront my partner about it, but at the same time whilst I still love him I can't bear the thought that he lied about cheating on somebody, even if I wasn't actually the victim in the situation.

Advice would be appreciated!!
<bot>: SO may very well have not ended his previous relationship before starting this one, and lied about it. Don't know how to confront him.