That's St. Valentine's skull resting in Santa Maria in Cosmedin, a particularly ancient church near Rome's Aventine Hill. You can keep your whips, chains, and poorly-written novels and screenplays. I'll take the Christian tradition any day.
Second, some background. I grew up in southwest Missouri, an upbringing that has provided more than I could have imagined when I was experiencing it. At this time I just wanted to GET.OUT. like many teenagers. Anyway, some of the irritation came from what I have since labeled "the aesthetic of nice," as in "that's a nice house/car/hair-do/boyfriend/girlfriend/baby/dog/tractor/business." Nice things meant "above average," "more than sufficient," desirable, and perhaps even domesticated. This survives today because I know same-sex couples from SW MO (and other areas of the country) who employ this aesthetic to describe their own houses/relationships, etc. What's good is "nice." So let's be clear: I am not pinning this aesthetic on evangelical Christianity (the predominant cultural version of Christianity there).
the point-->Valentine's Day was "nice" -- an entirely respectable, acceptable, domesticated holiday wherein both sides of a romantic relationship were scripted, understood, and expected. No surprises. In fact, you considered yourself lucky/blessed when you (finally) found yourself in a relationship so you could participate.
The aesthetic of nice makes the following so darned awesome:
The diners' utter shock is the aesthetic of nice, and the Catholic truth of our "nice" American romantic holiday shatters it. In good Chestertonian form it does so with humor, but also realism. So why do we remember St. Valentine's martyrdom with chocolates, flowers, and a nice dinner? The real St. Valentine met his martyrdom at the hands of Rome's pagan imperial power. To be true, the associations with romantic connections came later, but the fact remains: St. Valentine died as a witness to the Faith, not sweeties and sentimentality. Those are fine in proportion, but let's not mistake our cultural interpretation for the radical tradition.
This cartoon never gets old, especially when shared on Facebook with friends back home. It offers a new version of an old (but ever new) message: being Christian doesn't culminate with merely being nice--we are to confess Christ's death and resurrection. Ultimately, belief trumps rationality, and that is why Christianity always exihibits that unsettling weirdness, and even terrifying weirdness, that modern life either disregards or is completely baffled by. (And, as a former mainstream Protestant, I should add that the world also tempts us to conclude we can believe without the weirdness. It took a while, but I've since concluded that is wrong. You need not always embrace it, but its existence can't be denied or ignored. What was that about preaching foolishness? [I Cor. 1:18-25]) Roman Catholicism speaks joyfully about the Theology of the Body but the world basically plays the role of the cartoon's shocked couple--surprised horror at what really is the case. The Theology of the body is a far more radical--because it goes back to the Gospel roots--vision of marriage and sexuality. That is worth remembering. Anamnesis--the Church does so at the celebration of the Mass (Catechism #1099). In our own lives we, too, must remember where and how God works in our lives and through others. And on St. Valentine's Day that remembering focuses specifically on the one with whom we share our life and our whole self. That is surely nice--but also so much more.