Dear Ex 2018 (Taiwan), also known as Who Fell In Love With Him First? is Taiwan drama premiere on Apr 22, 2018
When the husband dies, wife and son discover that he made his life insurance policy out to his male lover. The woman reacts with anger and the son with confusion. Gradually, they begin to close in on the man, discovering the life the woman's husband had hidden from them.
(Source: Far East Film Festival 20)