At times laughter is part of a defence mechanism.
My xx girlfriend was offended while her late Father's casket was being lowered into the ground, his friend was laughing. Aside from the xxgf who was choked up, I thought it was nice how everyone understood it and let the laughing man be, while this sweet little old lady sang acapella like a bird while the box went down.
Another funeral I was at was celebratory. I recorded his sons do a final toast by his open casket by the ditch, he then emptied the rest of the bottle of Absolute Vodka on his Father's dead body and closed the casket. Minutes later a guy on a ukulele started shredding away while we chanted...
🎼I don't want, the mash up you're married wiiiiife......I don't want to mash up your married wiiiiife..... ( High then low and again )
If someone laughs I think it's fine.