She then asked the police officers if she could get her son's wedding ring.
Turns out, Thompson isn't the first Oklahoma man to propose while under arrest.
Police body camera video captured the moment between the couple on the Fourth of July, a moment that caught even officers off guard.
Thompson's family had been celebrating his birthday and Independence Day in their front yard when police showed up to the scene.
Brandon Thompson had demanded permission as he was being arrested to propose.
"When the other officer told me he was gonna propose I think my initial response was, are you kidding me?"
"When you're in love with somebody and you know that you want to spend the rest of your life with them, you just want them to know how you feel", said Thompson.
And his girlfriend said yes.
Keith said yes, and officers moved Thompson's handcuffed hands from his back to his front so he could place the engagement ring on his new fiancee's finger.
"Hopefully it will help him make the choices it will take to support his future wife and his kids", Anderson told CNN. "I guess it's like an unconditional love, you know?"
"I asked the officer if I could propose", said Thompson in a phone interview with CNN.
Anderson also hopes the proposal will send a larger message to the public - one that showcases the humanity of police officers. He was released on bail the next day. His next court appearance is scheduled for July 17.