Joe's husband, Dillon Passage, partied with Bryce on Bryce's boat Sunday in Marina del Rey, where witnesses tell us they hung out with Bryce's crew to celebrate his 30th birthday. Huge milestone, for sure. We're told Bryce had his boat parked and had only 15 people at a time every 2 hours. The rest of the partygoers hung out on the dock and beach area.

The obvious question ... how'd Bryce and Dillon even meet? We're told after "Too Hot to Handle" streamed on Netflix, Dillon hit up Bryce to show some love and say he really enjoyed the series. We're told they stayed in touch, and when Bryce planned his birthday party he invited Dillon.

And, how's this for a birthday wish ... we're told Dillon and Bryce each downed a couple of shots and Bryce wished for Joe to be freed from prison. The party -- which included several other "Too Hot to Handle" cast members, including Harry and Matthew -- went pretty late. Actually, pretty early. We're told it lasted till about 5 AM.