It's gentle to start with.
Fleeting, promising even, exploring....., then bolder, then withdrawing, then fleeting.....again. Then promising.
You can write it how you like.
It's called mating and it should be a beautiful, personal experience.
Sometimes all that is required is a kiss on a beautiful cheek at the end of a fulfilling day. In the sunset. An unspoken promise, to do this again because it feels so good.
To meet again tomorrow, to take it further.
That's enough to have every man and woman cartwheeling on the grass.
To touch their cheek, as your tongue is dancing with theirs, to invade and withdraw together, feeling that same sensation, feeling that....enclosure. Like a cage, your mouths locked together, in bliss. And it rises, wanton, desperate, to lock into them to impart all that you have. Heart, mind, soul, your breathe. Your oxygen. Your could happily die there.
You don't. You die in other ways.
Looking into their eyes, knowing that a kiss brings you closest to them.
It is what you remember most.