Romeo Beckham Shows Off Butt, Genitals In Soaked White Shorts

Romeo Beckham's jet ski skills are impressive ... but we doubt it was anyone's main focus during a wet and wild Ibiza getaway ... because his soaked skivvies revealed everything below the waist!!!

David and Victoria Beckham's son was spotted on vacation with his girlfriend Kim Turnbull Wednesday ... speeding around the clear blue water in a pair of tighty whities ... which quickly turned into a see-through situation.

When Rome hopped off the watercraft and onto the boat's deck, his shorts were absolutely soaked ... revealing his backside ... and the rest of his Beckham family jewels.

David is famous for his soccer skills on the pitch, but Romeo showed off his own personal soccer balls ... confidently sitting in full view of cameras.

The Beckham boys aren't shy at all ... we saw Cruz Beckham around this time last year shoving his package into his GF Jackie Apostel's face -- and she looked totally over the moon about it.