It's fine as long as both the parties involved are okay with it and if it doesn't disturb the public in a bad way. You know, like, some people do dumb stuff to impress their partners and end up causing trouble to the onlookers, often unintentionally. Sometimes your partner may not be comfortable about doing flashy stuff in front of public which kinda makes it awkward for them even if they like you. I'd say you shouldn't do that.
Yeah, it is possible that some people do that to avoid rejection as most people who're compassionate wouldn't wanna reject you in front of everyone. And doing it in public isn't always a bad thing though. For some people, it's like announcing to the world that I love this person and some people love it when their partner shows their love for them openly.