A proposal of marriage made by two young children for fun (ex. when playing house), or for real. Neither is expected to uphold their end of the bargain, and it is often forgotten as the children age
We were so young I did not expect him to remember our sandbox proposal, but here he is eighteen years later with a ring.
This is a phrase you use to describe the person that's been your best friend or one of your closest friends since the "sandbox." Implying that you've been together since you were young. The sandbox is the place babies or little kids play together at; this is where it started for the two of you.
A delightful sexual act in which a male urinates into a womans vagina before or after sexual intercourse. Preferrably afterwards... but then again.... This act is usually done out of spite or in rare cases for fun.
Reggie wasnt impressed with his girlfriends actions at the local frat party so when they got home he gave her a soggy sandbox and told all of his friends.