BE MY BABY as a parent tag to BBEMYBABY

BBEMYBABY's identity comes from the merging of both Idolm@sters and BE MY BABY (see here https://www.nicovideo.jp/watch/sm28073785); It would be better if it had a direct connection rather than both being separate entities. I would also like to note that BE MY BABY should also be the primary parent as that is it's the main thing being sampled and what the source is most well known for.