Do you think it or rude to fart during sex/sexual acts

So a lot of times when I go down on my boyfriend I notice there is a really horrendous stench like rotten eggs and a nasty smelly fart and I have always suspected that he is farting but was too embarrassed to mention anything but today we was playing drink or truth and I asked had he ever farted and he said he always farts when I’m giving him head or during sex he said because I hadn’t complained about the smell he thought they mustn’t of stunk so I hadn’t noticed 😭😭😭I’m sorry but whether they smell or not I think it is just such a rude and disrespectful thing to do