Searching for a reaction

Ok. Tell me how you would react. Long story short. This person has had inconsistent behavior. I've just kept an eye on it for the most part. I think it's quirky. But, it has eroded my trust a bit over time. That being said...the other day we were talking about the weather. Not sure what to wear out. And they said..."I don't have my phones". To which I said..."what?" And they got all weird saying they don't know why they said it in plural, they meant to say phone, they don't have another phone, and cursed. Then proceeded to project that I was in my head and ask what I was thinking. (Mind you, we have had this discussion before about them possibly having another phone.) But, my little alarms weren't going off in my head and I honestly didn't have any feelings at the moment. I kept checking in with myself and.. nope, felt like it was an honest mistake. But they were in a tissy. They kept going on about how they always make things plural (Which isn't true) etc. And I'm over here just like a potato. Fast forward a couple days. They make me a smoothie for breakfast. And as I leave for work say "don't forget your smoothies". And I look at them like huh??? And they say.."plural". Now.. now I'm suspicious!!