Yes, they often do! Flavoured lubes are a great way to add an extra element of play to oral sex, but they do contain sugar. Sorry! But worry not about your sugar diet - just make sure you are not prone to yeast infections - as sugar promotes yeast growth. Glycerin can have the same effect, so either make sure you wash properly afterwards or stick to a normal lubricant for intercourse. Keep the flavoured lube for oral sex experiences!