Feeling insecure

I saw my fwb the other night and we were talking about how he’s not on dating apps and he’s like yeah haven’t been for a while but I kinda got banned. So I said if he wasn’t banned he probably still would be on them and he’s says yeah but like I just have to probably get a new number and all that but can’t be bothered. We both kind of said that it makes us feel better and less insecure that the other person isn’t seeing anyone else and he said if he were too he would tell me (idk that would happen🤷‍♀️)

Two days ago we were texting, and last night I get a text from a number he didn’t say it was him but he responded to the last message I sent on his other number. So I said to him “oh did you actually get a new number the other night was a light bulb moment” and he goes “hahah nah I ordered this a few days ago my other phone was getting bothered too much”. I then go “you could never have texted back and I wouldn’t have known and been ghosted haha” and he’s like “I would never do that, that’s very dog”

I feel really weird about it now, like did he actually get a new number to go back on the apps or is he telling the truth, I know I shouldn’t really care too.