If you’re still nervous about a big height difference, Google “Shaquille O’Neal and Nicole Alexander kiss. " If the 7'1” basketball star and his 5'2" girlfriend can kiss, you won’t have a problem. [3] X Research source
It may sound silly, but practice kissing the back of your hand. Practice kissing gently, avoiding a tight pucker.
If they react well to your touch, that’s a great sign. Obviously, if they pull away or look uncomfortable, respect that. That’s a great way to know they aren’t ready to kiss, without getting rejected in a bigger way.