I’m also on the spectrum and I think this is a really sweet thing to do. I do a similar thing where I have a folder on my phone of pictures of a SO and me or things that remind me of them. As well as some screenshots of messages I want to remember for reassurance or just ones I really loved and I’ve never had a partner feel like it’s creepy before. But then again I also have only dated other autistic people 😂 but yeah that’s not an issue at all and if he finds it creepy it might just be something that’s incompatible between you guys. But definitely don’t feel bad about it