I would rather get caught singing in the mirror, rather than getting caught spying on my crush. I would rather get caught singing, because I honestly do think that it's much less embarrasing than getting caught by my crush spying on them. Both things have happend to me and I really do think it was harder to explain to my crush what I was doing staring at them. It's really awkward to try and explain, on the other hand singing in front of the mirror isn't all that bad, because thats also happend to me, and I will just get some kind of compliment like "oh you sing really good Chels!!". So yes I much rather get caught singing in front of the mirror.
