Well typically speaking the arbitrager, but the real answer is the lease agreement will outline who is responsible and it is technically negotiable.

If one tenant moves out or unexpected repairs pop up, the other property can help cushion the impact.Of course, more properties mean more responsibilities...double the maintenance and potential headaches.

Some very good responses here, but there is a better question to ask. 

You will not succeed as a real estate investor if you are fragile in your response to criticism.

No response to messages.

What we do is hard work and a lot of responsibility.

Balancing growth and caution is crucial for those leaving their W-2 job.Good luck!

For fix-and-flip investors, having immediate access to these funds is crucial, especially in a competitive market.By collaborating with an earnest money lending partner, investors can alleviate the financial burden of upfront deposits.

Make sure it's detailed enough on responsibilities. 

Great response here from @Michael Plaks (to what was a very long post, this is critical info).