Folding top set...

[FishRoller]

sux- its def a must-fold unless he floats to bluff situations like this (rare). You rele beat nothing so good fold (but gay one).

[Praetor]

nh, although against this guy maybe you can shove yourself/bet for value

[Marc H]

I don't like it. If he's that loose he could easily have 44, 55, 45, 4Q, 5Q, etc. I think you got bluffed.

[Jay Riall]

I would have value bet that river vs. this guy.

[pterodactyl_]

I bet this river, his range just seems like it could include many hands aside from the FD. Only thing is, with top set almost any bet will price you in to call a push unless youve got a very solid read.
As played good fold. Rough hand.

[Abramovic]

Often passive players are those capable of making the biggest bluffs.

I value bet this.