According to a series of tweets from Ismail, basically he logged into Destiny one day and discovered he had a new mail from the Tower’s Postmaster, which contained a message from Wallick that basically saw her propose to him in a short but sweet letter, to which he was more than happy to say yes to.
So this is where Bungie got involved. The developer created a special artifact called the Ring of Eternity which has been described as, “for Guardians who have found their perfect match.” It also seems that Bungie went through the trouble of creating a special emote for the occasion which saw Wallick’s Guardian on a bent knee proposing to Ismail.
Now it seems that this proposal could have been botched due to the recent DDoS attacks, but thankfully Bungie managed to get everything back up and running which saw the proposal go off without a hitch.