"He's too p***y to fight me again."

The first fight was wild ... with Jake getting the victory when Deji's camp threw in the towel in the 5th round of their bloody slugfest.

Deji was spending some of that hard-earned fight money on Rodeo Drive this week when he was asked about the possibility of the 2 YouTubers beating each other up in the ring again -- but it sounds like it ain't happenin'.

Why?? -- "He's too scared to lose the title."

But, Jake Paul ain't the only guy Deji's beefing with right now -- turns out, he's in a real-life feud with his own brother, KSI.

KSI is reportedly furious with Deji after his lil bro posted KSI's bank statements online. Deji also made some scandalous claims involving his brother and a woman.

But, Deji says the feud runs deeper than that -- explaining, "There's a lot of stuff my brother's done."

Doesn't seem like they're even close to burying the hatchet at this point which is crazy considering how close they were.

Deji also says he's got a big problem with KSI's crew, "The Sidemen" -- a group of British YouTube stars -- and says he's never really been cool with them.