Beaches can be perilous places, which reminds me of an incident from my service days. We had successfully arrived at the beachhead rendezvous point and set up camp but suddenly found ourselves surrounded by savages, armed with loud colorful shirts. The buggers did not even bother to tuck them in. Decisive action was required so I drew out my revolver and neutralized the threat, plus several teenagers, who together with an Olympic sized swimming pool, appeared from nowhere. Unfortunately, as it turned out, I was in Hawaii, plus it was 2007, but how was I to know these waiters were friendly? Always terrible business when innocent civilians are harmed. However, in my head, I had the safety of my men to think of and now; you have the welfare of your grandchildren to defend.
One cannot be too careful with these bloody foreigners, plus they have completely infested the entire globe. For all you know she may be plotting to elope with this stranger fellow and take the grandchildren as well. Accordingly, decisive action is required to prevent certain tragedy.
As you know nothing about this foreign chap then consider a shoot first then ask questions later strategy. A travel accident or perhaps even a drug overdose would certainly do the trick. Better safe than sorry eh, plus it could save a few shillings on Christmas, birthdays and divorce costs. However, it is ultimately your show and I will let you determine if there remains any latitude for a less conventional remedy.