One is a need, one is a want
You could switch between them to taunt
One is big, seems small
The other, vice versa; maybe caused by a ball
One being roots
While one maybe wanting flutes
If it's a special day, you stand in front of the mirror
And Pride yourself in having one or both (without a shiver)
Both need a nose; sweet or stinky
And maybe like the lizard, one needs to be slinky
Both might make you a big time flouncer
Now solve it and find relation between title and answer.
P.S: answer is easy, relation is hard
it's another answer all together...