My best friend came to me in tears last month. She said her new resale HDB flat needed urgent plumbing work and asked if she could crash at my place for three weeks while the contractors finished the toilets. We have known each other since secondary school.

I did not even think twice before handing her a spare set of house keys. She moved in with two large luggage bags and a quiet grateful attitude. For the first week, everything was fine.

We ate dinner together after work and shared stories on the sofa just like old times. Then things started feeling slightly off. I noticed she would lock the master bedroom door whenever she took a shower.

At first I thought nothing of it because people value their privacy. But then I found a receipt for two cinema tickets dated a Tuesday night when she supposedly stayed home sick. A few days later, I came home early from work because my stomach felt bad.

The moment I unlocked the front door, I smelled men's cologne in the hallway. It was definitely not my boyfriend's scent because he uses a very specific citrus brand. I walked quietly down the corridor and stopped right outside the master bedroom.

The door was slightly ajar. I pushed it open and saw her former boyfriend sitting right on my bed eating takeout food. He is the exact same man who broke her heart last year and caused her to cry on my shoulder for months.

She looked up and panicked instantly. She did not even try to apologise or explain herself. Instead she just begged me not to tell our other friends because it would ruin her reputation.

I stood there holding my handbag and feeling completely betrayed. I opened my home to help her during a difficult period, and she repaid me by turning my private space into a secret meeting ground for the man who destroyed her. Now my flat feels contaminated and I do not even want her sleeping another night in my room.

Should I pack her bags right now and tell her to move out immediately

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