Why are people revealing secrets spilling the tea instead of the beans lately?

The Wikipedia entry has sourced its answer from the Oxford English Dictionary entry for 'mackem'. As far as word origins are considered, probably as authentic as it gets.

EDIT: As it seems that everyone cannot access the OED link, here's an excerpt. There are two possible origins attributed:

Probably with allusion to the phrase mack 'em and tack 'em and variations thereof, freq. said to refer to the shipbuilding industry of the region

or..

Perhaps partly also with allusion to the pronunciation of make typical of Wearside, as contrasted with that of Tyneside.

Most commonly I hear it used by people who generally say "my boyfriend" ("My boyfriend is from Chicago") but might say "the boyfriend" when they find themselves saying something stereotypically what someone would say about a boyfriend, e.g., "I got my hair cut today, hope the boyfriend likes it!" or "I think we're free on Friday, but I'll have to check with the boyfriend!"