WARNING: This post is rated Adults Only. Children (including university students) should not see that adults with respectable titles like 'scientist' waste their time doing studies such as that reported here.
There's apparently no end to the marvelous, unpredictable, exciting, deeply penetrating insights of modern science--your tax money at work! Now, at long last, is proof of the harm that evolution has wrought: Keeping awake for sex can kill! This notable story is fair warning about fair damsels: keep away unless drowsy. The buildup of fluid pressure, or that sudden 'surge,' can trigger bleeding on the brain. So, at least if you must indulge, keep it from a climactic ending and keep your wits about you. Of course any other gushing (if less blushing) behavior can have similar effects, like blowing your nose. But they don't get into the news.
On the other hand, another study shows that happy marriage reduces the risk of stroke, so something has to give. This may be the phenomenon of 'marital bed death', in which couples are happier if they keep their hands off each other. At least, that's the implication. Marriages in which a certain manifestation of groping fondness for some strange reason persists are risky, it would appear, if this comparably penetrating study is to be believed.
One way to resolve these apparent differences is to note that sex and coffee are not limited to marriage, so that marriage confounds the understanding of the causal connections. Unless being married is the stressor, and sex only the correlate rather than the cause. Presumably extracurricular adventures would also have to be considered, but the authors didn't, so far as we're aware, peek into such affairs.
The bottom line, so to speak, is that you have to pick your poison. Keep your hands to yourself and keep your head clear: decide where you want your fluids leaking--on your brain or elsewhere.