Flop w 3way, board wet. SB massive fish 76/21
BN 23/13

Possibly BB range is low pockets, some Ax suited, some suited connectors, SB any2 cards possibly.
If called my equity is not very good, I should face an Ax, sometimes pockets, and most of the time a SD/FD. A check seems reasonable. Also Turn and River might bring me some good cards. An 8x, Jx, sometimes Qx will be good.

Turn is an 8x which is kind of a good card for me as it opens a OESD. Getting a 1bb donk from fish and tight player folds.

River is a Jd, which completes my SD but also completes a FD from flop.
V overbets 50 to 40pot, so my odds are 50:90 or 35,7%. He is a fish, he doesn't need that many Tx in his range for my odds being good but I am not so sure about calling here.