Learn English – specific word for describing a person who gets lost easily

How about a spoiler or a heckler?

Edit: There is also a Wiki article that says:

'exposure in magic refers to the practice of revealing the secrets of how magic tricks are performed'.

I am not sure how the term 'exposure' can be used as an agent noun to refer to someone who does the 'exposure'.

I don't have a single word, but an informal American expression would be

someone who can dish it out but can’t take it - someone easily criticizes other people but does not like it when other people criticize him or her

To dish out originates with the sense of serving food to people, but has taken on an idiomatic meaning of meting out severe punishment or criticism. According to Etymonline, this sense of dish dates from 1934. Taking criticism, punishment, or abuse is from the sense of take as receiving or accepting, from which the idiom taking heat also derives.

While this quality is a characteristic of narcissists, in lay usage narcissism refers mainly to self-absorption or vanity, rather than being simultaneously hypercritical and thin-skinned.