An insincere person should not be trusted
Your countenance belies your insincere request.
He made a show of caring and wanting to help, but we knew he was insincere.
An insincere apology is no better than no apology. I noticed that she was insincere when she said the shirt that was too small for me looked good.
The word 'glib' means fluent but insincere.
lacking sincerity; "a charming but thoroughly insincere woman"; "their praise was extravagant and insincere
No.
yes
Please tell me how to properly utilize the word "bunkum" in a sentence. When I lost my job, my brother's offer to let me stay with him turned out to be nothing but bunkum. "Bunkum" means "insincere talk". "Bunkum" is a variation of the word "Buncombe".
sincerely
Hypocritical.
It can depending on the person and it also depends if you are the one being unfaithful/ insincere or if your spouse is.
Sometimes yes. When somebody wants to flatter someone for something in return, or for putting them in a good mood, they will be insincere. But you never know, they might be sincere or not. But if someone is just commenting to flatter you because it's true, such as really close friends, then no it isn't insincere.