"ruin the moment" is a valid phrase in written English. You can use it when you want to express that something has made an enjoyable or special moment less enjoyable or special. For example: "I was about to propose to my girlfriend, but unfortunately my mom chose that moment to barge in and ruin the moment.".
"Ruin the moment?" he exclaims.
I didn't want to ruin the moment with accusations.
Our point is that if you endlessly discuss things it can take too long and ruin the moment".
She had a puffy little moonface, and Kevin loved to kiss the soft belly of each cheek, but within five minutes something always happened to ruin the moment.
Accused me of ruining the moment.
Would I collapse in ruins the moment I met a patient who reminded me of Ruth?
"It totally ruined the moment, but I remember thinking, this is my first real park moment".
Ludwig does not simply clarify my doubts with English writing, it enlightens my writing with new possibilities
Simone Ivan Conte
Software Engineer at Adobe, UK