R Markdown - When in line ifelse statements do not run they leave grey lines on the html output

I have a Rmd script that contains conditional in line r code.

eg. if(x %in% y) {ifelse(length(values)>1, "values", "value")}

However when I output this as a html file, there are lots of grey lines left in place of the ifelse statements that did not run.

How do I remove this from the output?

Example