Relationships on Facebook

What is your opinions on relationships on Facebook? And couples communicating through Facebook? Personally me and my oh are "in a relationship" on Facebook and I will occasionally tag him in a funny post / meme but apart from that we don't communicate on there. It really makes me cringe when couples are all lovey dovey on Facebook. And most of the time it's all for show. Why write on your oh's wall what you want for tea or tell them that you love them? Why not send them a private message? Personally I think really insecure people make a show of "he's mine" by writing stuff all over fb. Another one I hate is big declarations of "he bought me flowers he so amazing, thank you babe!" Why not just thank him in person? Urgh!