adulting

The use of adult as a verb meaning ‘to behave in an adult fashion, in particular by shouldering responsibilities even when they are unpleasant,’ is a bit of a running joke.  There are T-shirts saying ‘Not going to adult today’ which are evidence of the popularity of the idea.

The example of use that I like best comes from a website called Tiny Buddha:

I don't want to adult today. I don't even want to human today. Today I want to dog. I'll be lying on the floor in the sun. Please pet me and bring me snacks.

Whether this joke of the last few years becomes a permanent feature of the word adult remains to be seen. At the moment it appears only in the phrase going to adult.

I was going to adult yesterday until I saw the pile of washing.  

There are  popular stickers saying I adulted today and I adulted at work and such things, but this is a very contrived existence.  The Urban Dictionary recognises the verb and gives a nice example sentence:

Today I adulted when I took out a loan for school without my parents being there.

But there is not much evidence of natural use in the community.

Apparently the Urban Dictionary first registered adulting in 2014.  The Google Ngram shows that adulting has had a steep rise in frequency since then.