It's improper to drop in on him so casually.
I'll drop in on you when I have time.
Let's drop in on Nick when we're in Bristol, shall we?
Will you drop in on us tomorrow evening for a talk?
Be sure to drop in on me when you can spare a moment.
I thought I'd drop in on you while I was passing.
Will you be able to drop in on us for a chat this evening?
More than half of visitors drop in on the page because they've heard about it from friends.
When I was in Paris last week, I decided to drop in on Andreas Schleicher, the programme's architect, to get his views on PISA and Shanghai's education system.
If I had a time machine I'd visit Marilyn Monroe in her prime or drop in on Galileo as he turned his telescope to the heavens.
If you've got time, you really should drop in on Winnie the Pooh at Hundred Acre Wood, and have a quick bounce with Tigger.
We know that God is not an absent God. He does not just drop in on us every now and then, but he is with us all the time.
In the evening the frequenters of the house drop in one by one.
From early morning our neighbours would drop in one by one to have their bath.
