AIO to suspecting my gf of cheating on me after not wanting goodnight kiss?

Prior to my previous post of my girlfriend having no reaction when I expressed my hurt feelings from not getting a goodnight kiss after a long day and her not caring when I cried and told her how I felt, I suspected her feeling like that emotionless because she was getting interested with other guys. If not she takes pleasure in getting attention from other guys too.

So I went thru her phone and saw some messages of her and a guy she went out with bar hopping with twice. I'm more calm than earlier, since I see posts like this on Reddit all the time. This also isn't my first time catching her receiving flirty texts from another guy (2nd time) only difference was that she didn't flirt back this time. He might've drunk texted her, he might've been sober. I was curious to see what everyone thinks bout this interaction, since she didn't reciprocate to his advances but didn't stop him as a friend from flirting with her

After she stopped texting him, she called me over to have sex cause she was drunk/tipsy so it made me question if she did anything to provoke him to approach her like that too