Always remember this - the audience's imagination is much more wonderful than ANYTHING you can show on camera.
In horror - a saw coming in towards someone's leg and then cutting to the face screaming.
In this case, great suggestion about the wiping lipstick away.
Here I think you serve your audience better if you pay special attention to the music and pacing of the shot. Give it a slow build.
If you can imply them going in for the kiss... maybe cut to the actors hands - his hand on her back or in her hair depending on the intensity that you imply and her hands near his hip.
Again here more than anything the score and music is going to be crucial.
Or this... if you have a long kiss... and it's a high school thing
Have them in the halls (breaking the PDA rule is always fun) standing underneath a clock...
show them moving in as you tilt and or pedestal up to the clock. Put on some Luther Vandross

stay on the clock for a while (and please do NOT include the lip smacking sounds of kissing) and then come back down to show the actors pulling away and then her wiping her lips.
REMEMBER... the longer you are on the clock (or any other similar devices) the more time your audience has to let their imagination roam