This song seems to exist with two names - Be Kind To Your Parents & the similar Be Kind To Your Parent.

Parent song from "Young Vs Old" album - https://youtu.be/DPz9TpTG6HY

Parents song from "For Kids And Just Plain Folks" album - https://youtu.be/gGO1JdLMLx8

They are the exact same song - the "Parents" version was released in 1967 and without the plural in 1969.

It would seem that when it was re-issued someone at the record label erroneously dropped the plural

[Chords]
       xx3211
      x32310
      x13331
      xx0031
    xx1211
    xx0331
  xx2013


[Chorus]
   
Be kind to you

r parents
       
though they do

n't deserve it
              
Remember that 

              
grown-ups is a

 
 difficult sta

ge of life
        
They're apt to

 be nervous
    
and over excit

ed
              
confused by th

              
eir daily stor

      
m and strife

[Verse]
             
Just keep in m

             
ind, though it

       
 seems hard, I

 know
            
Most parents o

              
nce were child

            
ren long a-go,

    
 In-credible!

[Chorus]
   
So treat them 

with patience
    
and kind under

standing
              
In spite of th

              
e foolish thin

           
gs they do
     
Some day you m

ight wake up
        
and find you'r

           
e a parent too

!