This is both adorable and embarrassing... but Isaiah's adorable, melt-my-heart, reaction beat out my embarrassing, why-am-I-recording-this, singing.
Don't worry about that beeping you hear at the end. The sensor lost it's signal because Isaiah was kicking since he was so happy.
And for those that can't watch it because you're at work, I give you this- Isaiah's reaction to my singing:
I live for these moments.