Advice

my bf M (23) and me F (21) we have been together for 3 years. he lives with his mom and and brother.

i recently found 2 “girly things” such as bows and a pandora necklace that are not mine in his room. I thought nothing of it and asked his mom but it was not his mom or brothers girlfriend. Also I’m really close with his mom and she would tell me if some girl was with him. The first time i found something i just thought it might just be nothing . When i found the pandora necklace today i freaked out. He doesn’t have time to cheat on me because he works so much and I’m with everyday. i went through his phone multiple times and he hasn’t gave me a reason to think he has… but another thing that doesn’t belong to anyone in his household doesn’t make sense ? And when I confronted him he came up with 2 different stories and then he admitted to lying because those are two different stories and he said he “lied cause he was scared to loose me” and even if these things where mine why would he lie? That’s a serious thing to lie about. I don’t know what to think or do can someone plz give advice