>>58447422you can say "i'll have to watch lia today in light of lumi's unforeseen cancellation" (this is what i would go with, because of the bilingual pun, which also maintains your alliteration) or "i'll have to watch lia today in lieu of lumi", but not "watch lia today in lieu of lumi's cancellation". the things before and after "in lieu of" have to be the same kind of thing (substituting one stream for another stream), but the way you used it you had two different things (substituting a stream for a cancellation?).
