Tie the Knot
DEFINITION: If you "tie the knot," you get married.

EXAMPLE: Last weekend, we watched John and Sarah tie the knot.

SIMILAR IDIOMS RELATED TO LOVE AND MARRIAGE: Get Hitched; Ball and Chain; Head Over Heels
"[One of your editors] has become my new favorite person. I don't know how to express how much she has helped me with school!"
Name Intentionally Withheld
Undergraduate Student
UCLA