[joseki]

I think you played it fine. I read him to hold exactly 5c6c.

I guess it's possible he's slowplaying something or turned a set, but in that case he wouldn't want to face the field with two. He could have Ax, but I think the A would have bet flop almost always and you have outs against most of these. There's a decent chance he's got a better K and you're drawing pretty live against these (albeit, mostly to chop). A middle pair is another real possibility here.