Giggle Slut 

Someone who laughs constantly at jokes, whether they are funny or not. They make you not want to tell jokes anymore.

”Angelica is such a giggle slut, she laughs before I get to the punchline!”

Giggle Slut by Giam May 28, 2018

giggleslut 

One who giggles frequently, often at things that would not be commonly funny.

"Man, Mat was being such a giggleslut tonight. He laughed at everything I was saying!"

giggleslut by Bootylicker123 June 9, 2014