Ok so i must get the id you posted here to be confirmed and then hope that mine gets confirmed too. So i must accelerate the id you posted in a way i dunno and then after it is confirmed they watch in my id and confirm it?
I have a tendency to write complex things... sorry
![Grin](https://bitcointalk.org/Smileys/default/grin.gif)
I'll try to explain it a big more new user friendly... I'll have to ommit certain details, so don't take this story as the complete bitcoin theory, becuase it's heavily simplified...
Each transaction is basically a string of text that explains which inputs are used to create one or multiple outputs. As long as a transaction is unconfirmed, it only exists in the volatile memory of the nodes, so it's pretty unsecure.
The only way of securing a transaction is when it's added to a block, thus gets a confirmation. From this point out, your transaction will be written in a physical file on the disks of hundreds of nodes, so it will no longer exist in mempools only (as a matter of fact, it gets removed from the mempool once it's confirmed).
In your case, the sender received an output from transaction bbf69880c3464b7c6f316738b0f496580186ff051ebf25396fc6efc7f128f83e, but instead of waiting untill this transaction was included into a block (so the transaction no longer only existed in the memory of a bunch of nodes), he used the output of this "pending" transaction as an input for both your transaction AND the double spending one.
So, if transaction bbf69880c3464b7c6f316738b0f496580186ff051ebf25396fc6efc7f128f83e gets dropped from the mempool of most nodes, or if the creator of bbf69880c3464b7c6f316738b0f496580186ff051ebf25396fc6efc7f128f83e decides to double spend the inputs used for bbf69880c3464b7c6f316738b0f496580186ff051ebf25396fc6efc7f128f83e, both your transaction as your competing transaction are now using inputs that no longer exist on the network... In this case both your and your competing transaction will be dropped...
So, your first order of business should be to make sure that the input for your transaction is actually confirmed... After this is done, your transaction has a much higher chance of getting into a block as the competing transaction