Question for you guys? Am I overthinking this?

So a couple of months ago I caught my SO texting a woman he used to know. He asked her for a pic she never sent one, they chatted for a while and a couple of times he asked what she wa doing that night and it was always a night that he was obviously with me. We live together and we have a son together and one on the way, so it would have been obvious if he was just gone meeting someone. He told me when I found out that it never meant anything and he fucked up and he wouldn’t throw his family away over her that it was just an ego boost. In the back of my mind I wonder had she ever said yes to meeting up would he have done it or was he really just playing the game and leading her on? He told me he would never have actually hung out with her.