SIGYN:

“don’t be so quick to thank me,” she is not odin who calls upon
you in your darkest hour and expects you to become a flashlight
of a person for all that he has done for you. (which, in her opinion
is often NOT A LOT.) she will never give you something without
handing over the fine print and a magnifying glass too.

but it’s up to him to use this.

                                        “one day i might call on you for a favor.”

and that’s it. what sort of favor, how deep the hole will be that she
will dig when the time comes is not known. whether or not he KEEPS
the gift now is entirely his choice.

“and i found it not far from here, but don’t tell anyone you got a new
 one. or who gave it to you, okay?”

          ^{talk about being an ominous goddess. riddles might come next,
          he sardonically assumes, along with ambiguous prophecies.
          might be too optimistic for the favor in question to be something
          along the lines of him fulfilling some kind of acceptable ~sexual~ 
          desire, or maybe eating the rest of a cake she can’t seem to finish.
          nothing good ever comes out of getting yourself indebted to someone,
          but he’s got to admit – this is the first time he’s ever owed an asgardian
          something.}

           ^{really, he isn’t sure what a comparatively insignificant man like him
           could really offer a woman of her stature & power. at the very least,
           it’d be interesting. so accepting isn’t as much of a problem as it
           should be, considering that he lives for moments like this –
           unexpected, exciting, adventurous.} 

               ^{“ okay, godfather … but hey,
                 why don’t you want anyone
                 to know you gave this to me? “}

          ^{maybe he’ll regret accepting this gift one day.
          part of the excitement is not knowing.}