I used to play Mabinogi with my girlfriend (she still plays).
Great marriage system and you can have a home, a farm, a family, and couple bonus when grouping together.
http://wiki.mabinogiworld.com/view/Marriage
http://wiki.mabinogiworld.com/view/Family
The game is also very good. Mabinogi has a ton of features and things to do. Unlimited levels because of rebirth. Very great story telling with the generation quests (they're also a lot of fun). Mabinogi is probably one of the most complete, well rounded MMOs out there right now.
A TON of character customization. This game has been around for years, and won't disappear anytime soon.
I'd recommend it. The battle system is quite fun, and they're doing a lot of rework and new updates every single month since release.





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