I’d love a drama with SML or ML being her ex-husband or boyfriend.

Twenty Again - not a fantasy. A late 30's woman starts college because she hopes this will stop her husband from divorcing her. Her education stopped when she had their son at 20, and he has made a point of telling her intellectually unequal she is. Her son is a student there, and her husband a professor ... as is the man who was in love with her in high school.

Hello, I might be repeating some titles here. 


It's not clear who's the ML:

Bridges of Love She's caught between her ex and her fiance. 

Summer's Desire 


ML is the ex:

Payu Sai 

Rang Mai Hua Jai Derm But he doesn't know (alternate universe)

Deja Vu Same

Roy Leh Marnya 

The Love Proposal you see them date and break up. 

The Devil Punisher but she doesn't remember

We Best Love: Fighting Mr. 2nd the only BL I'll recommend. they get together in We Best Love: No. 1 For You 

Cunning Single Lady 

Get Karl! Oh Soo Jung 

Discovery of Romance beware cheating

Familiar Wife But she doesn't remember (alternate universe)

Go Back Couple 

I Have a Lover 

Because of Love (If you want to cry)

Eternal Love But she doesn't remember (memory loss)

Here to Heart 

Memory Lost But she doesn't remember 

Moonshine and Valentine same (reincarnation)

My Sunshine 


SML is the ex:

Another Miss Oh 

The Good Wife 

Witch's Romance 

To Be With You 

Kimi ga Kokoro ni Sumitsuita