Search Results: should i sneak out

so a year ago, my boyfriend was still single (he was single for 3 years before he met me) and so he went to thailand to have fun and all. He told me all about it. From his activities to people he met there. He told me that he met this thai girl. At first he asked for directions but then ever since that day, they have been seeing each other everyday - she shows him around the city, etc.
Then few weeks later, she would always call him to see him and would go to his hotel to see him and knocking on his door. He got creeped out and sneaked out from the back of the hotel. Ever since then, he would try to avoid her. But anyway, one day, the hotel staff gave my boyfriend a keychain. And that keychain is from that same thai girl. It would say "Nam love Jake"
He has showed me this keychain before in the beginning when he was telling me this story. But last night, it was on his desk in his room and I was thinking "why does he still have it? why is it on his desk?"
I confronted him and he said "its just a memory. Its not like I ever had feelings for her, but its just a memory that I had a stalker once. Its funny"
I still got abit annoyed with it. I dont know if he's lying.
Should i not be annoyed? Should i let it go? or was I right to be annoyed about it?