Jake Paul to Dillon Danis, 'You Suck and I Hooked Up with Your Girlfriend'

Jake Paul is doubling down on his claim he hooked up with Bellator fighter Dillon Danis' GF ... and he tells TMZ Sports he WILL take their beef to the ring ... just not yet.

So, a bit of a crash course here -- 22-year-old Jake first called out Danis last year, saying he'd beat his ass in a boxing match because his "striking is super weak."

The 2 have traded insults ever since ... and Jake recently went to IG to tell Danis to "ask savannah about the time we hooked up," ... referring to Savannah Montano, an Instagram model Danis has been dating for a while now.

Fast forward to Monday, when Danis told Ariel Helwani he was offered between $4 to $5 million to face off with Paul to finally settle their differences in the ring (while also calling BS on Paul's most recent jab).

We spoke with Jake at Wild Card boxing gym on Tuesday about the huge offer ... and Paul said, "I don't know what he's talking about."

And, then Jake went IN on Danis.

"Dillon, I know you're watching this ... Just remember you're still a bitch and I hooked up with your girlfriend. Savannah, how you doing? What's good?"

Jake added ... "He's not worth $5 million. The only reason anyone knows who he is, is because he's used me and my brother's name to make a name for himself and he got punched in the face by Khabib [Nurmagomedov after UFC 229]. That's the peak of his career."

"He's Conor McGregor's best friend. That's all this guy's done."

Jake says he's not fighting Danis yet because it's not what the fans want right now ... but when the time is right, he's fully prepared to take him on.

At least one Paul brother will be taking the ring soon ... Logan will have his highly anticipated rematch with KSI on Nov. 9, which will be streamed on DAZN.