Nikki tells TMZ ... “Whatever makes him happy. I’m happy for him. But it was curious timing, considering that he was supposed to be in court for our trial today."

Despite his big day, our Bam sources say he managed to fulfill his legal obligations by hopping on a Zoom link to attend the trial during his reception.

There is, however, an explanation as to why the events fell on the same day -- sources close to Bam reveal Bam's wedding was actually planned back in October.

They settled on Socorro County, New Mexico, because they knew they'd be filming their movie "Collecting Souls" in the area, in which Dannii's the lead. But it just so happened, that their trial got pushed back and landed on the same day as Bam's wedding.

It was only during a break in the court proceedings that Nikki and her attorney stumbled upon the story about his wedding.

Despite the clarification, Nikki's attorney, David Glass ain't mincing words .... telling TMZ, "We are currently in a bifurcated, separate trial on the issue of whether Nikki Boyd Margera should be treated as a putative spouse. It seems like a little restraint on Mr. Margera's might do him good."

David's point is Nikki believes her 2013 wedding to Bam was legal -- but Bam maintains it wasn't legit because their ceremony was held in Iceland where they were not residents, and they never did any official paperwork in the States.

As we've reported ... Bam's embroiled in a nasty custody battle with Nikki over their son, Phoenix - and, in addition, Tuesday's trial was to address the ongoing dispute about their marital status. The proceedings were continued into Wednesday.

Legal dramas aside, Bam was beaming with joy as he said his "I do's" with Dannii at the Val Verde Historic Hotel