Stay with a swinger, maybe and reproduce (9)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
propagate
'reproduce' is the definition.
(propagating is a kind of reproducing)
'stay with a swinger maybe' is the wordplay.
'stay' becomes 'prop' (I've seen this before).
'with' says to put letters next to each other.
'a swinger maybe' becomes 'agate' (I can't justify this - if you can you should give a lot more credence to this answer).
'prop'+'agate'='PROPAGATE'
'and' is the link.
Can you help me to learn more?
(Other definitions for propagate that I've seen before include "Develop" , "Advertise widely" , "diffuse" , "Increase by natural process" , "Breed from parent stock" .)