If you checked out the February 2017 LEGO Store Calendar here in the US, you can see there are two building events to celebrate Valentine’s Day. On February 11, there is a kids event to build a mini rose that they can take home. This event is for VIPs and requires a sign up.
Adults also get to join in on the fun on February 14 as they also have a building night. This event is from 6-8pm and it appears the rose build is the same as the one the kids get. Registration is not required but may be necessary if there is a lot of demand for it so you may want to ask an associate just in case. I know the Fashion Valley location has started taking sign ups so there is demand for it at that particular location.