Interesting! In Lancashire "To slope off" is to creep away hopefully un-noticed, "To sidle off" is the same but more brazen, I always thought that "relope" was associated with the former, with an allowance for the differing dialects involved.
On the singing of Hunting songs, it is of course quite common to sing of say "Adultery" I have done it myself without feeling that I should go out and do likewise! So don't let's deprive ourselves of some of the most descriptive songs there are and of course their glorious tunes.
Perhaps we are looking at this too closely, the Irish say of such a critic that "they would cut a Skylarks throat to see what makes it sing" we should not do the same.