Even in your wildest dreams could you imagine Taylor Swift serenading you at your engagement party?

Because that's what happened to Alex Goldschmidt and his fiancé Ross Girard this past weekend in L.A.

The couple threw a party at the Sycamore Tavern, and at one point during the festivities Alex spoke to the crowd, thanking them for keeping some details of the event secret, but that there was one secret he didn't trust any of them with.

"There is a person who is not here who sort of played a part in all of this. If you would give a warm welcome to my friend Taylor," Alex told the crowd, as Taylor walked into the room.

It turns out Alex emailed the "Delicate" songstress, and explained how her Reputation track, "King of My Heart," was a special song for the couple.

"This is from Alex... but sung by me," Taylor joked to Ross before she started her serenade.

Watch the adorable moment all captured in the video below.