The worst thing

Yesterday I had a very bad thing, it was the worst thing.
I had a party with classmates, and my boyfriend had a party because his best friend got married. We were in the different place in downtown, but we promised to meet when the party end. I enjoyed my party very much, but I had something on my chest about him. My boyfriend really likes to drink, and he often get drunk. When he get drunk, he often lose something. He had lost his lighters, necklace, rings, sunglasses, and a wallet. I was very worried about this his habit. I talked with my friend about this, and I said to her "He'll lose his cellphone next time!" as a jest.
I called him and sent e-mails him often as I could. A few hours later, I called him again, but he didn't answer the phone, and someone I didn't know answered his phone. I asked the man who answered his phone, "Who are you? Why did you answer this phone?" The man said to me, "This phone's owner lost this at the Ramen shop in Shimotori." I was really surprised to hear this. My joke turned to reality. I was in Shinshigai at that time, but ran to Shimotori to get his phone. The man gave me my boyfriend's cell phone and I said "Thank you very much." to him. After this, I called my boyfriend's friend to ask where is he now. His friend told me that he was at his home. I was really angry to hear that. I drove to his home and pushed doorbell. He came from his house with sleepy face. He was very surprised to see me, and laughed. He also said to me "Why do you have my cellphone?" and "How did I get home?". I couldn't believe this. He didn't remember how he got home last night. I got very angry at him at first, but I allowed him, because he felt very sorry about this. But he promised me that he will never drink too much.