[vsuperpower2021]

This still doesn't make sense. The connection between "feasting all day on a pig" and what you've described is non-existent.

[segmondy]

Yup, the fattening of the pig is "fattening the scammer's wallet". To gain maximum meat, you must keep feeding the pig, to gain the most, the scammer must keep the victim on the hook for as long as possible. The slaughter is the going all in to end the scam. Either by asking for all the remaining money if possible or terminating it when the victim is broken.