Have you ever dated someone who said all the right things and gave you a whole lot of affection, but it only ever seemed to happen in private? Did they become physically and emotionally distant in public? This was probably not a person who was in love with you. The right man will love making it clear that you're his woman and will never hesitate to put an arm around you or give you a massive bear hug in public.
Not that this is everyone's thing, but he would probably even love making out with you in public. If he's in love you'll notice that he couldn't be prouder to show you off to everyone, whether it's friends and family or random strangers. Public displays of affection aren't for everyone, but it's nice to show the world you love your partner.