Can the word 'BFF' be applied to decent adults like Senate members?

Solution 1:

It's not appropriate or natural to refer to adults as "BFFs."

"BFF" is usually seen as a goofy, over the top expression and thus is rarely used seriously by adults. However, it's not uncommon for a adults to use the over the top and goofy nature of the expression for comical effects.

In this context, the author is trying to humorously summarize the reasons some senators mentioned in the article gave for picking who they'll sit next to for President Obama's State of the Union address. Here, BFF is used to mock Senator Mary L. Landrieu's comment that Senator Olympia Snowe was "one of [her] best girlfriends:

“I asked one of my best girlfriends to be my date for the night,” Senator Mary L. Landrieu, Democrat of Louisiana, said of her choice, Senator Olympia J. Snowe, Republican of Maine. “Of course, we share the Small Business Committee.”