Bug/Issue Excess Gifts Still Grant Friendship?

I had a villager at 9 hearts and tried to give them their favorite item, forgetting that I'd already gifted them two items that week.
The game brought up the message informing that I cannot give them another gift this week while simultaneously granting me the achievement for reaching 10 hearts. I checked the Social menu and sure enough, they jumped up a heart and I still had the gift item.
I can't seem to reproduce this with other villagers at lower values so maybe it only occurs at the 9->10 step?

 

Related to this, I seem to have a thing whereby with my husband, he seems to have 13 of 12 possible hearts! I get the 13/12 from hovering over the star next to his portrait in his dialogue box. 12 is the max for your spouse, but 13? I fear that may cause a bug or something.

 

Had you actually talked to the villager that day before attempting to gift them an item? Their affection does get a small increase just from talking; maybe the game gives that small increase from your first actual interaction of the day with them instead of specifically checking if you're talking to them. I've gotten an achievement because a villager jumped from 4 to 5 hearts while just talking to them...

Not a bug. Keep talking to them; I believe it triggers something if you talk to them at 13/12 hearts at the right time.

 

Do you mean

that they gift you a stardrop

? If so, that has already happened!