Cat won't go home.

Hoping for advice on how to navigate this issue.

I would like to preface this by saying I am a huge cat lover and find it difficult to turn cats away.

I (F) moved into a condo mid last year, and one of my neighbours has an indoor/outdoor cat (Male/8Y)who is incredibly friendly.

At first he’d just follow me around the gardens, but over time he started visiting my apartment while I worked from home, sometimes (once every 2-3 weeks)even staying the night. I always leave the door open so he can come and go as he pleases.

In January, he spent four consecutive days mostly with me, only leaving briefly to eat and use his litter box. His owner then asked me to please keep him out at night because he wasn’t going home, which I completely understood and agreed to. This seemed to work for a short time.

Recently, my boyfriend also moved into the same complex (different unit), and the cat adores him.

Over the past month, things have escalated. He now refuses to go home at all. He’ll wait outside our apartments for hours, even in the cold and rain, rather than return to his owner. He also expects us to feed him and won’t go home to eat. He'll sneak in through open windows when he can. We love him and don't mind having him over but we also don't want to upset his human.

I’ve visited his home. He’s well cared for, has a comfortable space, good food, water fountains, toys, and a loving owner who’s understandably upset. She says this is completely out of character for him after 8 years.

We’ve tried taking him back to his door, but he just follows us right back.

We really don’t want to cause any distress or “steal” someone else’s cat, but we’re also worried about him waiting outside in bad weather and refusing to go home.

TLDR: Neighbours cat only wants to hang out with us. Doesn't want to go home. His human is getting upset