He almost came - the eroticism of Finn sucking his fingers almost sending him right over the edge, but the vine wrapped around his cock cinched sharply at the base and stopped his orgasm in its tracks. It almost drove him mad, and it certainly removed all last scraps of rational thought.

He pulled his fingers from Finn's mouth and grabbed his cock, feeling the vine around it making it almost half again it's normal girth. It should have bothered him, but it didn't. Instead he just ran his slick fingers over both, smearing the pre-cum with it, and then finally positioned himself to press the blunt head of his cock against Finn's entrance - which he watched as a tendril of a vine dipped in, then another, pulling it open for him--

"Oh fuck-- Finn--" He moaned as he pressed his cock along side those vines and started pushing both himself and the vine wrapped around him steadily and deliberately into Finn's perfect, waiting body.