When I was JW, my standard answer to "Saint....Anything" day was "Well, I am not Catholic." That's still a valid answer that I would feel like giving if I was seriously questioned on any Catholic or religious holiday, although I might change it to "Well, I am not Christian."
But fun is fun. I have no problem with gift exchanges at Christmas- because that's when people do that. St. Patrick and St. Valentine have been turned into something fun. This one has also been turned into something of a sexy/romance day. Enjoy.
SO HAPPY VALENTINE's DAY. Just a light-hearted thought.