It's not weird since a kiss on the forehead is a sign of respect and love in many cultures. A kiss on the mouth on the other hand is what most people find weird.
When I was a kid, my first trip to Italy experiencing the common cheek kiss handshake was mind-blowing. Just like a handshake, it to has variations. There was: the single, the double, the hovering, the silent (no smack sounds), the silent hover, and the way you pronounced the "smack". It has to have just the right amount of air-suck sound with no buzz or vocalizations.