My experience at MENSA meetings was a bunch of people bragging about their IQ. Many had their IQ listed on their name tag.
I've never seen that at Mensa in Germany, Hong Kong, Netherlands, Malaysia, UK, US, or elsewhere, really.
In fact, the matter of IQ has rarely if ever come up at all (except in abstract discussions of testing, factor analysis, operationalisation, objectivity/reliability/validity, etc.).