Hi there,
You do not need to get tested from this exposure. The HIV virus dies within seconds of leaving the human body, and does not live in air or water. If your friend did have HIV, he could not pass it to you from splashing water on you, even if you both had cuts on your hands. We are not seeing HIV being transmitted this way in practice at all.
I hope this helps ease your mind about this splash – let us know if you have further questions.
Health Nurse