When a friend returns from a vacation - in Ireland, for example - and decides that they want to see you upon their return, that's nice, right?
Well, it would be nice if said so-called friend didn't bring back a very nasty tummy flu. So far I've "enjoyed" 12 hours of vomiting, 36 hours (and counting) of quease, strained muscles in my chest and - the only good part - 10lbs lost. Now, if it were only the weight, I'd say "come on over anytime, I mean it!". But the rest?
If you, for any reason, have an upset tummy do not ascribe innocent reasons (like the recent gunshot wound you've received, or the arsenic you've just ingested) to said upset tummy. Assume the worst and STAY AWAY. Far, far away.
Your friends will thank you.