verb
dissemble
dih-SEM-bul/dɪˈsembl/
To hide true feelings or motives by pretending.
She dissembles at dinner, pretending not to mind the criticism.

Etymology
Imitation becomes a means of concealment: presenting a false appearance masks what is real. To dissemble is therefore to hide one's actual thoughts, feelings, or intentions behind a misleading seeming.
In context
But why should not I tell thee outright that which troubles me? I am not used, at least for these many years, to dissemble.
More examples
- He dissembles his disappointment with a polite smile.
- They dissembled their motives by claiming they wanted to help.
- Instead of dissembling, she admits that the decision upsets her.
Forms
dissemble · dissembles · dissembled · dissembling
dissembler noun — Someone who hides true feelings through pretense.