As human beings, we like to smooch. So naturally, us artists would like to know how to draw people kissing. The truth is that it is not as hard as you think. If you can draw a face in profile, it is a snap.
As always, before you draw anything, look carefully at photographs of people locking lips and you will notice something. During your quest to learn how to draw people kissing, you will see that people tilt their heads to avoid mashing noses. Usually this tilt is between 90 degrees and 45 degrees.
First, draw a head the way you normally would. Eyes closed and mouth open, if you prefer.
Now just add the contour of the other person’s face at an angle. Pay attention to the cheek bone and the eye socket.
Now just finish up the head. That is it! Now you know how to draw people kissing. It is really as simple as that. If you are having trouble, remember to think in three dimensions and to use photo reference when you need it.
Below is another example with less tilt which you might find easier.
If you are still having trouble, I recommend that you pick up the facial expression book by Gary Faigin which will help you define the muscles of the face. I have personally found it to be the best on the subject.