<human>: Can you give me the gist of the text in a nutshell?

Was driving back home with my girlfriend the other night, when we happened to pass a Devonshire tea billboard. All of a sudden she just burst into laughter, to my amusement I asked her what was so funny. 

She proceed to tell me that back in her dorm days she wanted to talk to her friends about me, but her issue was that the walls were pretty thin, so if anyone just happened to be passing by they could listen in on her conversation, resulting in news being spread like wild fire. Her solution to this problem was code naming me "Devonshire tea". 

Her reason for naming me Devonshire tea came from the association of the country town which I grew up in as kid. I found it pretty cute, but it's taken 8 months and a billboard for her to remember to tell me about it =P
<bot>: Girlfriend had a code name for me so she could talk to her friends without giving away she was talking about me.