i was going through and reviewing my recent post changes, and i noticed that post #3997283, post #3998508, and post #3998810 all show tag edits that i didn't make (i only added the posean tag, i didn't remove cub, or add the becoming_erect or heart_symbol tags. anybody know how/why this happened?

In the case of an alias or implication changing tags, that is only reflected in the post history once somebody makes another post edit.

That's just the way tag changes are effected by AIBUR requests that were processed between the previous edit and yours (issue #623) - It's not ideal, but it's not anything to worry about either.