So the way you bring up a conflict in a non-confrontational way is to know that the research by the Gottmans shows that they way a conflict goes is actually determined by how it starts 96% of the time. So the key here is using non-blaming language so that your partner doesn't get defensive. There's three steps. The first is to make an "I" statement where you own your feelings. For example "I feel frustrated when..." or "I feel sad when...". If you find yourself saying, " I feel that you're selfish" it's no longer an "I" statement. The second step is to describe the situation using neutral language. For example, "I feel frustrated when you don't call when you're running late from work." as opposed to "... when you don't care enough about me to call me." And the third step is to ask for what you want with specifics. "So, I ask that you call me whenever you're running late. Would you be willing to do so?". If you use this kind of communication you will really set yourself and your partner up for success and will be much more likely to be heard.