I'm planning on a romantic subplot in my SciFi WIP, but I don't have any personal experience in dating, and I don't normally pay attention to how other people treat each other, so I'm not entirely sure how - besides the obvious "sex vs no sex" - romantic relationships are supposed to look different from friend/family relationships. So far, all I've come up with is: Volume. Romantic relationships seem "louder" in the sense that lovers feel the need to frequently remind their partners that they love each other, whereas friends/family seem to be more casual about leaving more unspoken. Is there anything else I should consider? I've tried Google, but everywhere I've found simply says "there is a difference between romantic love and family love" without going into a lot of depth about what the difference is, and I'm still working up the courage to ask my real-life family about their romantic relationships.