I was trying to say "During one of my girlfriend's soccer games..."
The problem is when I spoke it, it could be interpreted as
"Out of all of my girlfriends... during one of their games this happened"
"Out of all of the games that my girlfriend has played in... during one of those games this happened"
I have only one girlfriend, so how can I word this sentence so that when I speak it, it can only be interpreted as "during my one of my (singular possessive) girlfriend's games..."