I work supporting some code which has a separate developer. The developer has his own manager. This piece of code is now quite stable and there is very little support work and development. The developer's manager has asked him to work on some other code.
Since my work is now very light I have asked my manager if I can take over the occasional development that is needed. This will need very little ramp up time as I know the code very well. He was OK with the idea. However, said that he will talk to the developer's manager but has not done so yet. AFAIK, there is no organizational problems with this arrangement, it can be an informal one. There is no need for me to formally transfer.
Should I inform the developer directly about my request? I will be diminishing his responsibilities, but he has other things to take care of anyway. I have never met him, and have not talked to him about anything outside of work. He is quite nice, I am worried that he may feel that I am backstabbing. On the other hand, this whole arrangement may not even work out.