La bise is a greeting, not affection. The number changes by region (1 in some Nord departments, 4 in Nantes, 2 in Paris, 3 in some Charentes). Wrong number = awkward social moment.
Two embarrassing moments: 1) You lean in for two bises (Paris standard), and they lean in for three (Charentes). Awkward nose-bump. 2) You offer la bise to a business contact who expects a handshake only.
The other thing foreigners miss: la bise is between people of any gender in social contexts. With a woman (any context) it's the default. With a man, in most regions it's reserved for close friends and family — not work, not new acquaintances.
How many bises for your exact situation, and which cheek starts. (Hint: in most regions, you start on the left cheek — but some regions it's right.)
What to do if the person seems unsure — shake hand, nod, or wait for them to lead.
Where this breaks down — age gaps, religious dress, illness, formal events.
No. Quebec: 1 bise (gauche then droite, both cheeks). Switzerland: 3 bises standard (la bise suisse). Belgium: 1 bise. We're tracking France only here.
Politely refuse: "Je ne vous fais pas la bise" (I won't kiss you). Almost everyone understands. Air-kiss (la bise dans le vide) is also acceptable.
At formal/business events, yes — handshake is safe. At parties, follow the lead of the host. At a casual social meet, you can offer your cheek and see what they do.