Justin Bieber Kissing Playboy Model -- The Biebs Pulls Yet Another Hot Chick

Justin Bieber is on an absolute tear in Ibiza, and his latest conquest might be his best -- the Playboy Playmate he held a late night make out session with on a yacht.

Biebs was photographed hooking up with Miss July 2013, Alyssa Arce on Thursday night. Our sources say she and Justin met on Wednesday ... and ended up hanging on the same yacht. Funny how that happens in Ibiza.

22-year-old Alyssa is signed with Wilhelmina LA, and we're told she hit it off with Justin almost immediately -- but it's nothing serious just yet.

As one source put it ... they're just "having fun."

Amen.