Bob: “Do you want to go out some time?”
Gala: “I don’t think so Bob, but thanks.”
Bob: “Can’t blame a guy for trying.”
Gala: “Thanks Bob! Have you seen these green beans?
“Thank-you, but no.”
(Shake head a little making direct eye contact. Small but determined smile.)
If he persists, be straight:
“No pheromones.’ (Shrug shoulders, put up hands in a *what can we do? * manner).
I’m not sure how you back out now that you’ve made plans. I’d probably chalk it up to experience, go, and be determined to have a fun time. Cut it short if it becomes too awkward. If you just can’t bear to do it, cancel as soon as possible.