Mark Wahlberg & Diddy -- We Pay Our Bets ... Even the $250k Ones! (TMZ TV)

Diddy and Mark Wahlberg have a mega bet for $250,000 on the Mayweather-Pacquiao fight -- and unlike a lot of other big time betters ... the loser in this wager is actually gonna pay up.

We know this because Mark says they've got the money sitting in escrow! Yeah, super rich people bet differently from the rest of us.