Having noticed that it's our 7 year civilisation anniversary, I dispatched barakta to the interwebs to find out what the traditional gift was. The interwebs' suggestions were confusing and naff, so I propose a new system: Anniversary gifts of elements, in order of atomic number.
Naturally, in light of current events, I'm now thinking it would have been useful if we'd procrastinated a bit less.
A friend suggested that nitrogen would be a fun gift in its liquid form, but a cursory google search lead me to semen far quicker than I expected.
(OTOH, if you go by the years we've actually been together you get potassium, which is also an exciting gift option...)