Sean “Diddy” Combs is in a real nail-biter after a partial verdict was reached Tuesday in his federal criminal trial -- and the mogul tried to calm his family's nerves.

Diddy turned to his mother, Janice, seated behind him in the second row, after she asked him a few muffled questions inside the NYC courtroom. Diddy then leaned in and whispered to his mom, "I'll be alright" and "love you," while thumping his chest.

The Bad Boy Records CEO also said something under his breath to his six adult kids, who were present in the gallery, including Christian, Justin and Quincy. The children then exited the courtroom with sad faces.

This isn't the first time Diddy has shown his affection toward his family during the 7-week trial, making similar comments throughout.

Of course, all of this comes against the backdrop of a dramatic Day 2 of deliberations ... the 12-person jury reached a verdict on 4 out of the 5 charges against Diddy -- namely two counts of sex trafficking by force, fraud or coercion and two counts of transportation to engage in prostitution.

The jury was hung on the racketeering charge -- but the judge tasked them with continuing their deliberations Wednesday.