Is there a way to get a free second phone number without needing a second phone?

I want calling and texting to a phone number other than my cell number, although I want to get notifications on my cell whenever I get messages. I definitely need inbound calls and messages, and outbound is strongly preferable as well. Ideally it should be able to come onto my cell phone and one other person's cell phone as well. I want a low cost, and free if at all possible. If you know of any such services please let me know. Thanks!