I'm cool with Jews who argue that Valentine's Day must be ignored because it’s not a Jewish holiday. It isn't, and I ignore it, too.
However, the cranky old contrarian lurking deep inside me, feels the unexplained need to remind you that upshurin and Lag B'omer bonfires were also borrowed, or copied from non-Jewish rituals. In fact, those who recoil from Valentine's Day and studiously avoid eating turkey on Thanksgiving should know that the origin of the bonfire and the upshurin are much more suspect
It's all here. (Scroll down to the letter from "Seth Mandel.")