Tmesis

Tmesis (Anc. Grk. 'cutting') is the process of separating the parts of a compound word back into the smaller words.

Music Lyrics
"We don't have to keep on oneing-up each other", from "Hey Girl" by Lady Gaga, Florence Welch

The tmesis occurs with 'one-up', which is commonly conjugated after 'up' rather than after 'one'