Super hot, all-day long birthday sex. LOL, no, not yet any way. Maybe a good book, something he has always wanted, या a rare, hard-to-find copy of a प्रिय author's work. Damon seems to enjoy reading, so somethng along those lines Elena could give. Maybe, a very nice कमीज, शर्ट या jacket-black of course.
I think Damon will try and get Stefan back for Elena's birthday. Elena would probably प्यार that gift and it would दिखाना how much Damon loves Elena and how selfless he is when it comes to her.