quick stud 8/b question

[Big Poppa Smurf]

i like to play horse, but this is by far my weakest game. i don't have the hand history here, but this is a very general question so it shouldn't matter too much.

a 4 brings it in, i raise with (K8)K since there are like two low cards out behind me, and a guy with (xx)7 3bets me. I call.

Fourth: he catches an ace, i blank off. he bets. call or fold here? i think this might be a fold, but i decided to call.

Fifth: he catches an 8 for a board of 7A8, and leads into me. easy fold right?