Advancing a pseudo-counter in an align environment

I’m getting some strange results I don’t really understand with the following code:

documentclass{article}
usepackage{pgfmath}
usepackage{amsmath}
newcommandinitializecount{defaecnt{0}}
newcommandaenextify{%%
  pgfmathparse{int(aecnt+1)}%%
  xdefaecnt{pgfmathresult}%%
  typeout{>> aecnt}%%
}

begin{document}

initializecount
Current: aecnt
begin{align*}
  aecnt && aecntaenextify
  aecnt && aecntaenextify
  aecnt && aecntaenextify
  aecnt && aecntaenextify
  aecnt && aecntaenextify
  aecnt && aecntaenextify
end{align*}

end{document}

Resulting in the following

It’s as if each aenextify command is being expanded once when the align* environment is first parsed and then again as each line of the environment is expanded. What I would like to do is start the counter at zero and after each line of the align* environment, advance this counter.

I tried inserting a noexpand, but then the pseudo-counters are completely ignored or had no noticeable effect. (In this MWE, the noexpand itself just seems to be ignored.)

aecnt && aecntnoexpandaenextify

Please note that I’m not interested in actually using LaTeX’s native counters, this is just a MWE that illustrates my problem. If you can get this MWE to work or explain why it’s failing without resorting to using real counters, then I’ll be very appreciative.

documentclass{article}
usepackage{amsmath}
makeatletter
newcommandinitializecount{defaecnt{0}}
newcommandaenextify{%%
unlessifmeasuring@%
  xdefaecnt{thenumexpraecnt+1}%%
  typeout{>> aecnt}%%
fi  
}
makeatother
begin{document}

initializecount
Current: aecnt
begin{align*}
  aecnt && aecntaenextify
  aecnt && aecntaenextify
  aecnt && aecntaenextify
  aecnt && aecntaenextify
  aecnt && aecntaenextify
  aecnt && aecntaenextify
end{align*}

end{document}