It was really nice seeing you again after almost two years

If you are so particular about using the gerund, I think you can say:

I came here for a meeting with my sister.

Just said that at 16.

Alan

You are right; it went unnoticed by me, Alan.

By the way, what do you say about the following sentence?

The police came there for arresting the thief. (I think here it is an intention/a reason)
Or should it be ‘to arrest the thief’?

I would say: to arrest …