I wasn’t here for that discussion. For what it’s worth this is my take of it.
You didn’t get into specifics such as who started the kiss etc. So I will say for examples sake that you are intiating the kiss. I will substitute I in this example because it helps me visualize the scene better.
I am holding your hand, we are walking side by side. Lightly tracing my finger on the inside of you wrist. We pause momentarily to take in the scene. Looking into your eyes I focus solely on you. You draw closer I smell you and can feel the restrained excitement. I shiver and you draw me into your arms to warm me, I wrap my arms around you. We are talking but it’s light and unimportant. Your heart is just a little accelerated, I wet my lips and kiss the nape, a couple kisses tracing up your neck, I nip it softly. You respond immediately, slightly startled. I bring my head up, direct, teasing, serious. There is a pause and I shake my head drawing away briefly bringing my hands away I put a finger to my lips moistening them as I do, before you respond I kiss your lips, placing my arms around your neck, the kisses are soft short feeling them with mine. Inhaling you, feeling your response, you start returning my pecks for yours, impatient. I pull on your hair a little softly but deepen the kiss, swallowing my excess saliva, sliding my moist tongue into your mouth. I take time to dance with your tongue as it meets mine at the entrance of your tongue. It’s not about force or power. It’s like being blind in a strange place. I taste you, explore the shape of your tongue, more is less, the movement how you follow me, if you engage and also advance. Don’t let it turn into a teeth mashing cavity search. Draw away a little before you want to nibbling a little on the the bottom lip before you draw away completely.
That is my interpretation of a first kiss.