Dating issues?

Gave a rose of romance to an NPC and the calendar scheduled to meet the next day between 3-5pm. Went to their house, clicked on them, talked to them, didnt get any prompting on how to actually start the date, no info at all. The NPC just acted like he usually does, only with an exclamation mark, with no way to address it.

How do I actually start the date? Did I encounter a bug? What's the normal prompt like?

Yellow!

No prompt you just get close to the NPC in its house at the giving time frame and it should start following you.