This actually felt like something that could happen in real life. Although losing your home keys (and possibly some other keys in the same ring) in RL would be extremely annoying and bothersome, maybe even disastrous, so I feel like the dude took it pretty calmly. I suppose it helped that he wasn't alone and he found out so quickly he will be able to retrieve them. It's sort of difficult to judge the romantic progress, but if we assume it's happening, the story isn't stretching it for extra chapters.