Bovada 6-Max .25/.50 cent blinds

The villain had been at the table with me for about 30min and appeared to be generally aggressive, but hadn't done anything that seemed too out of line to this point.

UTG
MP
CO
BTN (Villain) $62/ 124bb
SB
BB (Hero) $48/ 96bb

Hero is dealt J8

fold, MP calls .50, fold, BTN calls .50, SB calls .25, Hero checks

Flop (4 players, pot = 2.00) j10j

MP bets 1.00, Hero raises to 3.50, fold, Villain (BTN) raises to 7.00, MP folds, Hero calls 3.50

Turn (2 players, pot = 17.00) 6

Hero checks, Villain bets 17.00, Hero folds, Villain shows K10

I know its not typical to give the results of the hand in this forum but I was really perplexed by what the villain showed me here. I don't even know why he showed his hand. Did he know he had likely bluffed me off of 3 jacks and wanted to showoff, or did he think that his 2 pair was actually the best hand? Did my flat call on the flop and check on the turn show enough weakness that I was inviting a bluff? If so, is there another line I could take to avoid this error? Even if I did look weak, wouldn't it be more typical for someone with 2 pair to just check it down and hope for a showdown? Why am my asking so many questions?

You've edited the HH.
How does Hero in BB raise MP before BTN?
stupid

Lol I meant SB not MP. I think that should have been obvious

Villain is obviously very bad given his line so i dont think anyone would be able to understand what he was thinking
Also i guess he was bluffing

I wouldn't fold before the river. River will be close but I dont think you can fold this early in the hand

Its bovada lol. call call call