I went vegan straight away from vegetarian. Though I had been drinking soy milk for about 5 years beforehand so it was just a matter of giving up eggs and cheese.
You will find that there is a vegan alternative for most things.
I use nuttelex for butter, organ egg replacer for eggs in baking, tofu for making scrambled eggs, fried eggs and omelettes, soy milk and oat milk instead of dairy milk, and there are countless numbers of vegan cheeses:
http://www.unleashed.org.au/community/forum/topic.php?t=5461
You will find that a lot of restaurants (especially asian style restaurants) will be willing to make you a vegan meal, even if they don't have one on the menu. I'm not sure where you live, but I know on the Gold Coast and in Brisbane there are a lot of really nice 100% vegan restaurants.
http://www.happycow.net/australia/ < type in your postcode/suburb there and it should give you a list of vegan friendly restaurants where you live (:
If I go to someones house then they will either cook me a vegan suitable meal, or I will just make a big dish of something to take there so that everyone can have some of what I'm eating (:
If your partner is going to eat meat and dairy regardless then organic is better in terms of how the animals are cared for. Also I think there are some organic dairy farms in Australia where the bobby calves apparently aren't sent to slaughter.
Even if your partner doesn't ever go vegan, if you can get him to enjoy eating your meals then that means he is eating less animal products
EDIT: Sorry for the long response! Didn't realise I wrote so much ha.