I moved into a HDB flat in Ang Mo Kio with my best friend. We both pay S$1,500 rent and keep a joint account for utilities.

The account always had a small buffer for water and electricity. One evening I checked the balance and saw S$2,500 missing.

I asked her about it. She said she had an emergency and would repay me next month.

A few days later, while borrowing her phone, I saw a notification from a messaging app I didn’t usually use. The chat was with a man I had never met.

He was talking about wedding venues and deposit dates. She wrote, "The S$2,500 is ready, I just need to transfer it to the new flat.

My heart sank. The money I thought was for our bills was actually covering his deposit.

I confronted her again. She admitted she had started dating him secretly and was planning to move out.

She said she didn’t want to lose our friendship, but the money was the only way to secure the new place.

Now I feel betrayed. Our trust is shattered and the rent fund is empty.

I have to decide whether to stay and hope she pays me back, or to leave and find a new flat on my own.

Should I keep fighting for the money and our friendship, or should I pack my things and move out

What would you do if your partner hid something this important from you?