The singer showed off her bruised and horribly swollen foot and ankle Thursday night ... the apparent end result of Wednesday night's drama at L.A.'s Chateau Marmont. TMZ broke the story ... Britney got into a fight with current boyfriend Paul Soliz -- with paramedics showing up to tend to her.

In the video she posted, Britney tried to downplay the incident ... claiming first responders showed up "illegally" to treat her. As we reported, she refused treatment, but this video makes it clear she's got a pretty gnarly injury.

She says she just landed the wrong way while doing a leap in the living room at the Chateau.

She's clearly upset someone called paramedics to the scene, and she's blaming one person in particular -- her mom, Lynne Spears.

Britney's under the impression Lynne was not only the one who called paramedics, but possibly the paparazzi ... as one photo agency got the shots of Britney exiting the Chateau draped in a blanket and pillow.

She added, "I haven't talked to her in 6 months and she called right after it happened before the news being out!!! I was set up just like she did way back when!!! I wish I had grandparents!!! I can’t stand her!!! I honestly don’t care I will say it."

Britney's ex-husband had a far more peaceful update to share Thursday ... posting a shirtless hiking pic with Porsha, the Doberman he got while still married to Brit.

It's debatable what Sam's showing off more here -- his pup or his bod, because his 6-pack abs are front and center.

Remember, Britney and Sam shared 5 dogs together during their marriage -- with the model getting full custody of Porsha after their split. At the time, Britney kept her Australian Shepherd, Sawyer, her Yorkie, Hannah, and 2 other smaller dogs.

Sam's thirst trap upload has many of Brit's fans criticizing his timing ... calling it insensitive to her plight and injury.