Be certain to deal with each other in a straightforward, aboveboard manner over the next two years. You're both more open now than usual to deception, and any way that you might mislead each other -- including little white lies, the kind you might think you're telling in order to preserve your sweetie's feelings -- will only damage the sense of trust between you. Larger deceptions will be even more hurtful, of course, so if either of you is wondering whether the relationship is really where you want to be, be honest about your feelings.
It's best not to be hurtful whenever possible, but sometimes it's even more hurtful to keep your feelings and desires to yourself. This vulnerability to deceit can also happen to the two of you as a team, for example, if you get involved in some speculative venture together, such as investing in property and the like. Neither one of you will be able to read the red flags, so get the opinion of someone you trust before sinking any substantial money or time into anything. Finally, your combined energy level is lower now than usual, so don't expect more of yourselves or each other than you can deliver.