Player is relatively competent. Definitively a thinking player and doesn't really bluff all that much from what I've seen. When he bets big he usually seems to have strong hands. I guess the thing to think about is I think I played my line a little weird and want to know if this would induce villain to try and bluff me off on the river because he thinks I have a weak hand.

He limps. I raise it up for value.

I like to check call here as it let's villain do funky stuff. Not sure if leading here is the best option though. Or is raising his bet better?

I decide to donk here because I'm a fish. I don't really know what I donked and am not sure why donking is better thank check calling or check raising?

I think I should bet this for value. Since the three paired I'm not really wanting to go crazy here. Villain is limping 22% from the button and raising 46% so maybe 23, 22, 33, 37, K3 are in his limp calling range? When I get check raised I am getting 29% on a call and I end up folding. I feel like villain has to be really ballsy to bluff diamonds here against me because I could very well likely have a strong diamond or even a boat.

Do you guys call down in these types of spots just because it's headsup and people can do strange things? Thanks!

P.S. Later today in my session I got check raised on the river and ended up calling with the K high flush and villain showed a bare A for the nut flush blocker bluff. I didn't know fish are capable of check raising river with air! I rarely CR river as a bluff and wanted to know if people playing heads up at my level are doing these sorts of maneuvers?