we don't know if having hsv1 orally gives you any significant protection against contracting hsv2 orally. That said, not many folks have hsv2 orally in the first place and those who do, it doesn't shed very often at all ( like 3 days out of the year ). the odds of you sharing a drink with someone who has hsv2 orally combined with the odds of them shedding the virus on that day are astronomically low.
In other words, this is your anxiety kicking in.
grace
If you already have oral HSV1 the likelihood of contracting oral HSV2 are slim to none. I'm not saying it's not possible, but the risk is EXTREMELY low. Because you already have an oral herpes infection your body has built up anti-bodies to protect against another herpes infection. Also, if it was just a sip of soda that lowers the chance even further.