Oh!!! Thank you so much for this!!!
I suggest trying the following and see if it reduces the amount of burps.
-wash and dry your cucumber
-chop the ends off (slice one cm away from the ends)
-rub the ends you chopped off against the cut until you see a white foam form. Rinse off the foam from both the cucumber and the chopped end and repeat the rubbing until no more foam forms.
This milky sap is where most of the burp inducing bitterness is. Rubbing the parts together draws it out (to an extent).
-throw away the ends you chopped off and rinse the ends of your cucumber
-get a peeler and take the skin of the cucumber
-scoop out the seeds
-you are now left with peeled cucumber boats. It should be at this point less burp inducing but you can take it a step further
-slice your cucumber into thin slices
-spread them out onto a plate
-sprinkle an amount of salt onto them to your liking
-wait 30 minutes
-throw away the water that has come out
-now you can choose to rinse the salt off or eat them with the salt still on.
It's an interesting experiment to try an untreated cucumber next to a cucumber slice that has been salted and rinsed. You will probably notice the salted and rinsed cucumber slice is less bitter.
Or simply buy asian cucumbers and they have significantly less burp inducing cucurbitacin to begin with.