Is adultery of the heart the same as committing adultery in the flesh?

There are some who take Matthew 5:28 where Christ speaks of adultery of the heart as true physical adultery and thus grounds for divorce. I think this is a heart issue as noted in the context of the entire 5th chapter. Clearly lusting after a woman is a sin yet does it rise to the level of true physical adultery which may be grounds for New Testament divorce. I am looking for input on this issue. “But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart.” ‭‭Matthew‬ ‭5‬:‭28‬ ‭NIV‬‬ https://bible.com/bible/111/mat.5.28.NIV