Here are some signs you've been with your partner for a looooongggggg time . . .
1. One of you farts so loudly the cat starts, flattens his ears and hares out of the room (ok it was me) but your partner doesn't bat an eyelid.
2. While your partner is checking something on your laptop, you notice a bit of fluff on his sweatshirt and pick it off. Your partner says: "Did you just pick your nose and wipe it on my sweatshirt?" And what's more he doesn't sound particularly shocked! As though having bodily secretions wiped on clothing is a sweet declaration of affection. Either that or he has given up on any basic notions of decorum.
3. You discover that your partner (oh and this isn't me) has been picking their nose in the shower and flicking it, supposedly down the drain but somehow it ends up calcified to the shower wall like snot grout. And partner affects surprise like it's a charming little affectation. "If you had a new partner you wouldn't do this!" merely meets with a hurt look as though bogey blasting in the shower is an entirely reasonable activity. So you smile calmly and try to scrape it off. With a scrubbing brush, with a FINGERNAIL and finally with his toothbrush. This is very satisfying, especially when you watch him brushing his teeth the next day.