I think I’m falling for him…

I’ve been with my husband for 11 years. Never cheated, married 5 years. We have two beautiful kids. I’ve always been completely in love with him and never wanted another man.

I’ve had a really tough year with both my mental and physical health. Over the last 6 months I’ve become really close to a male colleague. He’s also married with kids (I’ve been to his house and met his wife and kids) but he’s a natural flirt like me. He’s been so amazing and supportive in our friendship and rings me when things have been tough to talk things through. He’s genuinely lovely and always knows when I need a cuddle off him and brings me treats like chocolate or drinks on the rough days. I genuinely would have been lost without him in work these last few months. But now I feel like I’m falling for him and I don’t know what to do. I know nothing would happen because we’re both happily married but he makes me feel so safe and warm when I’m with him. I don’t want to keep my distance as he will wonder what he’s done to offend me but I also don’t want to let my heart win. Any advice please?

Edit to add: his wife has seen how we are together and seen us hug and him kiss me on the cheek to say goodbye. I’ve told my husband he hugs me when I’m having a bad day especially and my husband says that’s ok because I need good friends while I’m struggling. He texts me all the time and my husband is aware of this. I think part of the reason I feel something for him is because he’s so like my husband- he’s very sweet and family centred and looks so similar to my husband. I do rely on my husband and we have a great relationship and sex life but when I’m at work and need someone it’s him who is there. He’s my work husband 🤣