HAPPY VDAY GUYS! <3
Sorry for the late post but here are some places you can consider going if you have not decided where to go with your other half yet/ celebrating a belated vday just like us:

Activities:
Airshow 2014 - 15th & 16th Feb (book your tickets @ sistic website, $25/ person)
Love lock @ Clarke Quay (review here)
Xcape (check out their web here)

Dining/bar:
Prive @ keppel bay 
Nox Dine in the Dark
Kombi Rocks Diner (check out their web on how you can rent a kombi!)
1-Altitude (review here)
Sky Dining @ Mt Faber Jewel Box [$$$] 
Faber Bistro @ Mt Faber (Went there once & the view was awesome! check out their review here)
The White Rabbit @ Demsey Hill (make your reservation here & read the review here)
Ben & Jerry's @ Demsey Hill (for dessert)
Ocean Restaurant by Cat Cora @ RWS Sea Aquarium (more details here) [$$$]
Revolving Restaurant @ Prima Tower 
Shuffle Bistro Bar @ Clarke Quay (one of our favourite places!)

xoxo, hope this helps!
P.S Boyfriends, please give your girl a flower/helium balloon even if she says there isn't a need for it (trust me & thank me later *winks*)