1.
If you rub a substance in , you press it into something by continuously moving it over its surface.
When hair is dry, rub in a little oil to make it smooth and glossy.
PHRASAL VERB : V P n (not pron) , also V n P
2.
If someone keeps reminding you of something you would rather forget you can say that they are rubbing it in .
Officials couldn’t resist rubbing it in...
The home side rubbed in their superiority with a further goal.
PHRASAL VERB : V n P , V P n (not pron)