Ducks catching nothing and drops the ball (5)

'drops the ball' is the definition.
The answer and definition can be both to do with social activities as well as being verbs in their -s form.
Perhaps you can see an association between them that I don't see?

'ducks catching nothing' is the wordplay.
'ducks' becomes 'bobs' (I can't justify this - if you can you should give a lot more credence to this answer).
'catching' is an insertion indicator.
'nothing' becomes 'O' (O resembles 0).
'bobs' enclosing 'o' is 'BOOBS'.

'and' is the link.

Can you help me to learn more?