I'm largely indifferent to sex in general but I've definitely read and enjoyed content with both vomit and sex! It really just depends on if nausea is a factor. If it's just forced puking without actual sickness, I'm not too interested in that. But if it's just like the rocking motion on an already upset stomach, that sounds good to me, I'm all for that.
Also this is weird, but I find that sexual content where there's full nudity to be like...way WAY more unappealing, as opposed to sex where they just move their clothing out of the way enough to get the job done.