Asteya
The third Yama of the Yoga Sutras is Asteya. Non stealing. Incorporating this yama in to our lives seems easy enough.
DON'T STEAL OTHER PEOPLE'S STUFF!
It should be obvious that our relationships will suffer when we take things that aren't ours. And not just grand larceny type stealing. Intangible stuff. Time. Energy. Work.

Don't be that person. Check yourself. Are you being reciprocal? Are you giving as much as you are receiving (notice I didn't say "taking")? Are you making everything about you and your wants and needs? Yes, you are the star of your own show but don't pull focus or steal other people's light.
If you feel this hits a little too close to home, then maybe ask yourself why. Recognize that there are other out there wo deserve recognition and consideration just as much as you do.