Question

consider The Last ride together as a dramatic monologue

Answer 1

Poem is a dramatic monologue where its spoken in voice of a male speaker highlighting on final ride with his lover after she has pointed that she doesn't want to change his feelings.  

Usage of word "mistress" doesn't imply an adulterous relationship in this region but refers to a female who is loved by the poet.  

Setting of the poem is not genuinely explained as we know that poet and woman set out for ride in the third stanza and we don't truely know if ride is legit/illusion.