At the very end of Orach Chaim 128:45, the Rema says:
אסור להשתמש בכהן אפי' בזמן הזה דהוי כמועל בהקדש אם לא מחל על כך
It is forbidden to be serviced by a Kohen even in our current time...unless the Kohen forgives it [willingly forfeits this honor].
The Mishna Berura (s.k. 175) there notes that if the kohen has some benefit, such as being paid, or serving an important person, there is less reason to be concerned, and the kohen is more likely to forgive this diminishment in his status. But for מלאכה בזויה (disgraceful work), one certainly shouldn't have the kohen do it.
I recall being told that if a group of yeshiva boys must clean the kitchen after Shabbat, they shouldn't task the kohen among them with taking the trash to the dumpster, as it is disgraceful work.
May a wife ask her kohen husband to do all the things one might normally ask a husband to do if he were a non-Kohen?
- So can a wife ask her kohen husband to take out the trash? Change a stinky diaper?
- Perhaps you'll say the husband is mochel on his honor. Teenage sons may well not be. So can the mother ask her teenage sons to do housework (clean their rooms, take out trash, etc), or more properly, if they reply that as kohanim it is beneath their dignity to do so, are they technically correct? While we might claim the mother is an important person relative to them, if they claim they have no particular pleasure in serving her, is she precluded from putting them to work in this way? How does the mitzva of kibbud av v'em enter into this?