this is bugging me

I just watched a video clip of a Joey McIntyre concert, and he was singing a beautiful song. I swear I've heard it before, but I cannot place it. The lyrics "Someone's breaking my baby's heart" are stuck in my head. Can someone help me?

I believe you are referring to the song "See Her Smile" by Jonathan Larson from his musical, "tick, tick...BOOM!" (he is also the author of the musical, "Rent").

Something's breaking my baby's heart
Something's breaking my baby's heart
Something's breaking my baby's heart
Oh-I just wanna see her smile