Should I Be Worried? Please Read Fully!

So I have my boyfriend’s IG on my phone still even though I was supposed to log out of it. He doesn’t know this. I already know what comments I’m gonna get regarding this but I urge you to answer the question in my caption about the bigger picture situation I’m about to explain...

So I saw he was messaging this girl from high school (my bf is 25 so he knew her like 6-7 years ago) whom he hasn’t ever mentioned to me before. Anyhow, she’s an extremely pretty, single mom.

Their conversation is SUPER NORMAL. I wanna make this very clear. Like it was just

‘hey how’s it going’

‘good, you?’

‘Good,how’s work’

‘it’s boring, how about you?’

‘oh I’m thinking of taking aboriginal studies at so-and-so college’

‘oh nice’

So I left it but then the next day I felt the need to check again and when I opened the chat from his account, all the messages were gone! Just *poof* vanished. And I was just like????

And today I get a notification on my phone saying “this girl, xyz, ~my account’s name~ and others have posted stories.” And I ignored it but I checked from his account just now he had viewed her story.

To be honest, I feel super bad about invading his privacy and DUMB AF about this post but I need someone to confirm that I’m just being stupid and none of this means anything?

Some context - I’m super insecure about this incredible weight I’ve gained this year and there have been absolutely no signs of distrust from him otherwise. He is consistently more forgiving and understanding than I am but idk why I feel he’s being a good boyfriend to me bc there’s something going on and not bc I deserve to be treated right.

Does the deleted/vanished messages mean something? Also I checked, you can’t delete the other person’s messages yourself. So they both would have to have deleted their own texts by themselves. Like it would have been an effort from both the sides not just one of them.

I welcome all the hate I’m about to receive but I hope at least one of you answers me and my concerns as well. I mean this sincerely even tho it sounds sarcastic I now realize but it’s not.

I just wanna reiterate that these were messages on his Instagram. And I wasn’t able to delete another person’s messages except for my own. Like it lets you press and hold your message and then the option to ‘Unsend’ pops up aside from ‘Copy.’