Still Possession

Was meeting someone

"My ex-Japanese boyfriend was etc...."

"......my ex-Japanese boyfriend said etc..."

I do know this is English grammar

I do know school teachers told us to put "my" in English

But every time hearing this expression, "my ex-boyfriend", I often feel

this woman still possesses him
she still holds an ownership of him
he is still her belonging
& man is just one of woman's possessions

Maybe true