Lines...from long ago

I fancied the thing with which we begat
those two fine lads we held so dear.
 
Yet, written as vulgar, is your lovely twat.
 
But...the dictionary...is wrong...I fear.  
 
This reputational status seems clear,  
and thus I think the topic needs more chat.
 
Yes! l well concluded, with much thought, and beer...
that I will always fancy the thing with which you begat
those many, many months of looking fat...
and you endured the condition with good cheer.
 
Then, in your rocking chair, with you, they sat...
those two fine lads we hold so dear!