Worrying about his ex...

Aina • Hi! I`m a 20 year old college student who loves to play video games and do nerdy computer stuff 🙃
Hey ladies and lads!
I've been with this guy for about 5 months and I really love him. He's smart and caring compared to the others I have dated. He motivates me and supports me in everything which I'm really grateful for. 
But sometimes, I just feel really insecure because of his ex. He still has pictures of her on Facebook and follows her on Instagram. From what he told me, they didn't end well so I have asked myself why he'd want those around. And now he tells me that he doesn't like pictures (but we've taken some). He rarely smiles (saying he doesn't like smiling) but in every picture with her, he is. It's also been a little over a year since they have broken up.
He's super nice and reminds me how much he loves me everyday. I don't really wanna talk about this with him since it might start an argument that really doesn't need to. Please let me know what you all did to overcome this if you've been through it before!! 😞😭