in

[Silverobama]

Hi,

Is the "in" necessary in this sentence?

Are you serious about moving back in or are you pulling my leg?

Thanks a lot

[Raymott]

Hi,

Is the "in" necessary in this sentence?

Are you serious about moving back in or are you pulling my leg?

Thanks a lot

It's not always necessary. It depends on where the person is moving back [in] to.

[Silverobama]

It's not always necessary. It depends on where the person is moving back [in] to.

So it isn't wrong but depends on the context?

[Raymott]

So it isn't wrong but depends on the context?

Yes; for example, you move back to Sydney, but you move back into your previous apartment.
If you have a roommate, they might ask, "Are you moving back in?"