I have been troubled by the 'giving him a reaction' but I will apply toddler logic to this.
A toddler needs boundaries. They will however push those boundaries at any opportunity.
I see little difference here. He's pushing his luck, he needs calling to heel. Solo, you do need to tell him off when he is overstepping the line.
I am aghast at the BB sending you messages, WTF is that about, what is she thinking? If that is not rubbing your face in it, what is it?
She is craving drama isn't she? All that time it was a secret, she got her kicks by stealing about and taking him from you and you never knew a thing. Now it's all out in the open, she has lost her edge, her secret. This is to get that guilty pleasure at having been a naughty girl?
Oh FFS. You have to ignore, ignore, ignore, she really doesn't need you to give her the reaction she so craves. Your Ex needed telling off, she needs nothing, you even breathe in her direction, she will have got something out of you, don't give her the satisfaction. Just change the number.
CHANGE THE MOBILE TODAY. I can highly recommend HTC Wildfire, they have everything you need, email, FB, Twitter all can come direct messages to you. Please Solo, for your own safety and sanity, you need to make this break.