Trust, of course, and friendship. My hubby and I are together 24/7 in a house that is 5 times smaller than what we were used to, and we're working together in the same (internet)business... If we weren't each other's best friends, we wouldn't be able to handle this situation, since there's not really a way to have some privacy (well, in the bathroom maybe haha)
We have the same weird sense of humour, we like each other's strange habits and also like to tease one another with that... We have always lots to talk about and love to make plans for the future and then work out ways to realize them (we call ourselves 'the A-team' hahaha, "we love it when a plan comes together!" tatatataaaaaa ta ta taaaaaa ) and what happens in the bedroom... stays in the bedroom . Oh and another thing is that we have learned really well how to fight and argue, so every now and then we have a quarrel... like a summerly thunder and lightning, a little bit of fresh rain to clear the air.