Is it not sailing on two boats?If two boats are sailing in parallel then it may not be that difficult to keep each foot on each boat though hardly it happens in reality and that's why it is said not to sail on two boats. Doing two unrelated things at the same time cannot guarantee success in any way as the concentration is divided to keep balance but there are certain things that people do to prove they are involved in both the tasks or at least their thought process is involved in both the tasks. I am giving an example of one particular issue and I expect opinions after carefully considering various aspects associated with it.
There are non-vegetarians everywhere though depending on the locality the concentration of that section varies. In many cases, it is found that such non-vegetarians turn vegetarians on specific days as they consider such days religiously/aesthetically significant. For example, on Thursdays or during the period they worship a God/Goddess they do not have non-vegetarian dishes anywhere. They do it because they think it is a sin to eat non-vegetarian dishes on those days while worshipping the God/Goddess. I fail to understand why it will be considered a sin on specific days and not on all the days. On one hand, you are showing your faithfulness and on the other, you are unable to control your appetite for a certain dish. Won't you call it sailing on two boats?