I love oral sex, but it's never expected and even my wife probably does it less than more, depends on the mood. If my play partner told me, sorry I don't do oral, I would be fine with that. There have been times where the woman I'm with does oral, but I don't let it go to long...want to avoid finishing early
One benefit to oral (experienced this as well as read in other postings) is it can get a guy hard when needed. This can be a remedy to the guy being nervous and not quite hard yet, or he's cum once already and needs to get ready to go again.