18 m/o smacking

[Ms2]

I have an 18 m/o little boy, he is a lovely little boy very well behaved normally but recently he has started smacking people in the family.
He is otherwise such an amazing little boy and i am asking if anyone has any advice as i dont want people thinking he is naughty or nasty.
He does give you a kiss after and knows he has done something wrong but i want this to stop, im just not sure how to? Any advice please!

A firm, 'no- we don't smack people' every single time. If you're in the middle of an activity, stop it and move away with him somewhere boring. Move back after a minute or two with a 'right, no smacking, ok?.' If he doesn't smack, lavish with praise. If he does, another 'no. No smacking. We don't smack people because it hurts.'

The key is to not make a huge attention giving fuss or a big tell off. Rather just say no, say why then make the situation dull when he doesn't behave. At this age your attention is what they want.