Use I feel statements. Do not say that somebody is categorically doing a thing or not doing a thing, say that you feel like they are doing a thing, and then explain why you feel that they are doing that thing and how that makes you feel. Do not judge them for it. Just clarify how you personally feel. That way you are not speaking to what they are doing, just how it is impacting you. Combine that with genuine communication and you should be okay. Be ready to make compromises. Be ready to listen to how they feel as well, not just to talk about how you feel.