As weeks passed since Andy's change as he swam along the coastal depths around where he's once lived. He was happy there but he'd begun missing the old world he'd come from even if he'd always wanted out. He'd wondered how his roommate had been doing and if he missed him. As he swam with powerful strokes of his tail he was drawn to a beach he vaguely remembered as one he and his roommate had gone to a few times. It was secluded and often empty, perfect for skinny dipping they would often laugh.
As he approached he saw a familiar face
"Andy?!" It was his roommate, Ian "I never thought I'd see you again. Where've you been, man?" he asked.
"Let's just say some odd things had occurred" Finding the air more easy than before, though still quite uncomfortable.
"What sort?"
"Come in and I'll show you." he said with a grin as his roommate began to strip. Never had he been so attracted to him. Never at all, really but he couldn't resist now. Ian tentatively walked into the surf nude.
Andy could no longer resist; he swam up and embraced him, coiling his long tail around Ian's legs.
"Huh?!" His roommate exclaimed in shock but then loosened up. He touched Andy's tail and felt the strange texture of it as it changed from human skin to scale around mid thigh. "Wow... so this is what happened to you?"
Andy nodded and asked "You like it?"
"Yeah, quite a bit" Ian said with a grin "Any way I could get something like that?"
"Thought you'd never ask"
The merman laid a kiss upon his roommate's lips to both their surprise. Again, he tensed and relaxed, both enjoying newfound pleasure in each other and their bodies as their rock hard cocks swelled against each other as Ian began to feel the transformation take hold. He writhed in a mix of pleasure and pain as his tail bone lengthened out of his body and his feet and legs fell away into nothing more than a pair of pectoral fins at his sides, surrounded by scales which again transitioned into human skin around his crotch and butt. They embraced for a long while as they pleasured each other by stroking each others still very human cock. They dove and frolicked in the depths in their new forms.