Flatmates

What's the etiquette around having your bf/gf to stay when you live in a shared flat?

My flatmate has gotten into a routine of having her bf over at least 3 nights a week. Now, she also stays at his place an equal amount of time, but to me it's starting to get a little unfair.

There's the inevitable inconveniences, like shower/bathroom congestion (i've been late for the bus a couple of times as a result), but it's mainly the awkwardness of the coupley-ness that does it for me. I can't really sit at the table browsing the net when they are snuggled up on the couch watching a rom-com together.

It's not awful, just uncomfortable. Time to move out I guess.