There's Only One Way to Say It?

Okay, I'm just warning you but this post may come across a little "Deep Thoughts by Jack Handey"-esque. So what's the deal with the strict way we refer to couples once they have coupled? In other words, I have these friends who are couples and whenever I refer to them as a couple, like "I'm going over to Heidi & Akhtar's," I never say it the other way around, "Akhtar and Heidi's." Why is that? It's Steve & Phuong, Row & Suger, Denise & Jeff, Mike & Agnes, Tom & Ag, Sunil & Steffi, the list goes on. I would never say Phuong and Steve's house. That just doesn't make sense. Do you think it has to do with who we think is the "heavy" in the relationship or is it simply whatever flows better? Because I know that many people use my combinations. I mean, who ever says, "Judith & Tommy's"? It's always Tommy & Judith's. Sit on that for a second or two and you'll see what I mean. Groundbreaking, right?