What's the Bat Boy secret?

I read the synopsis that came with the CD and they left out the most important piece of the puzzle- about why the mother doesn't approve of Shelly and Bat Boy's relationship. What's the secret? Is Bat Boy her brother? I need to know!! Thanks

Thanks for telling me. But how could they be related when neither of the parents are...bats. Did the father just create him somehow?

* SPOILERS *

I thought they were half-siblings. Didn't a bunch of bats rape Mrs. Parker, which resulted in Bat Boy?

Pheremones.

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"The pheramone was designed to be rubbed on the hide of a cow, to increase sexual stimulation in the bull..."

Dr. Parker spilled it on Meredith and then had sex with her "to say that he took me would be romanticizing the act, to say that he raped me would be unfair. ...he was acting beyond his own control... "

When Meredith was walking home the bats were attracted to the pheramone too and they attacked her "they bit, they borroughed, they borroughed EVERYWHERE"

Meredith got pregnant and had Shelly, but there was one more baby... The bat boy, Dr. Parker was told by meredith to kill it, so he took it out to a cave, but he couldn't do it, so he left it there "hoping that nature would in time do what I could not, but I was wrong: (sung) The bats your true fathers came and they took you down to your midnight lair... The bats your true fathers claimed you and made you theirs..."

pretty crazy...... When I saw it I couldn't believe it, it was hilarious.

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