Kissing: Is It A Sin?

Someone asked. What do you think?
Is it a sin?
My reply was, "for you to even doubt that it's not a sin has given it up as a sin".
But I guessed that, that answer was too ambiguous and based on faith.
So I decided to explain why it was a sin.
To be utterly frank, it's not kissing that is the sin.
It's what goes on in your mind that is the sin.
So if in your mind you like that fact that you're kissing someone (sexually) then it's a sin.
There are other fewer times when kissing is not a sin.
Like kissing a sibling on the cheek or mum on the head.
Or gesture of kissing that laid it's foundation on other emotions like Happiness, friendship (nonsexual), etcetera.
My point is, if your body told you it enjoyed it or you know your partner did, you either committed a sin or shared in a sin.
You shared in the sin in the sense of making someone commit a sin when you know doing that(kiss) would make them commit a sin. Even though you felt nothing (sexually) by kissing them but the same could not be said of your partner.
So kissing as a sin is complicated but in the Nigerian and African scene, where it's not a culture to kiss our loved ones, it unequivocally points to a sin with very little exceptions.