Did I do anything wrong?

I have been speaking to a guy for a few weeks and I noticed that he follows my ex ‘situationship’ but did not think much of it because I know men associate with each other through gym etc without being too friendly and we didn’t have a relationship so did not see it as a red flag. Anyway I went on a date with this new guy on Saturday and then he messaged me the following day as he normally would but when I replied he’s now left me on delivered for 20+ hours. During the time I’ve been on left, my ex situationship replied back to my story trying to make conversation which he sometimes does anyway. Is this a coincidence or are they closer than I think? It sounds like something was said about me but I’m finding it childish that he won’t just communicate that to me. Also I didn’t sleep with any of them and have only seen the situationship guy once 1:1 and all the other times have been in group settings. If I had known they are close friends I would have never went there and now I’m feeling guilty. My friends think I haven’t done anything wrong as we weren’t exclusive or dating but I can’t help the guilt I feel :(
Did I do anything wrong?
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