Is this all just friendly, or am I being paranoid?

OP, your posting style and the content seem really familiar. Did you post in a similar vein previously?

Interesting that you 'love him to bits'
Is he married?

Unfortunately the fact your asking this question OP actually answers your question. Obviously this working relationship is making you uncomfortable so it suggests boundaries are being crossed by you both. You sound like a caring attractive successful woman who would be there for your friends & colleagues if required. The problem occurs when there is a line crossed & people become so close, especially at work, the relationship begins to evolve into something more than initially intended. It's up to the people involved to make sure this doesn't happen unless they are happy to begin an affair & ruin families in the aftermath.

OP, having read your messages back, I think you are looking for reasons to talk about this man, who you objectively find attractive although you don't want to risk your family for him. I suspect you do rather like thinking about him and he's playing on your mind, which is why you are figuring it out here. Remember you don't have to move to his department if it doesn't suit your career, and you are in control as he is not your boss and you don't have to be any more friendly than how you are right now. We don't know his inner thoughts and neither do you. Just have a think about why you are posting all this.

It’s understandable that you're feeling mixed signals, especially given your past experiences. Your colleague's behavior does seem like a blend of personal and professional support, and while it could be entirely genuine, there are a few elements that might warrant caution.

His actions—like the extended conversations, personal compliments, and sharing private information—go beyond typical workplace friendliness, particularly since he doesn't behave this way with others. Even the comment about seeing you smile is kind, yet perhaps unusually personal for a professional setting, especially if he’s more introverted.

That said, the fact that he’s never crossed any clear boundary, like inappropriate remarks or communication outside of work, could indicate that he values and respects the professional boundaries you've both upheld.

It might help to keep your guard up a bit and observe his behavior for consistency over time. Continue being friendly and supportive but be mindful of maintaining boundaries that feel comfortable to you. If he’s genuinely just a close work ally, the dynamic will likely stay supportive without veering into uncomfortable territory. If his intentions shift or feel unclear, a polite step back in some of the more personal interactions (like those lengthy, non-essential calls) could help reestablish a strictly professional rapport.

Navigating this carefully may let you keep a strong, beneficial professional relationship without the risk of blurred boundaries.

I have many male friends too. I prefer to err on the side of caution in the office, though.

This is Mumsnet remember, opposite sexes can never be friends, one is always secretly wanting to shag the other. (Even though I’ve got very close friends of the opposite sex I’ve been friends with for 20 years and nothing remotely flirty has ever happened ).

Just to buck the trend, I have a work colleague who is male, I am female.

We don't share an office, he is much higher up than me, but we do chat daily, and if I'm at home we chat on speaker so my husband joins In the conversation too.

We chat about work, and our personal lives and anything in between.

I love this man to bits as a friend, but that's it. It does happen.

You are clearly questioning something here, is this something you want? Something is holding you back, do you know what it is?

Do you think senior management just came up with this or do you think he has been pushing them to move you to work more closely with him?

Personally I would say you need to do what you feel is best rather than wonder about him or his motives. If you are questioning this move, the old adage "If in doubt, do nowt" comes to mind. It's your career not his, if making the same moves as someone else was guarenteed success, we'd all be rolling in cash.

It’s a shame you base your worth on that and not just believe someone might want to be friends with you for you.

Who cares, though, as long as he's not inappropriate in anything he does or says? I mean people are allowed to fancy other people. It's not like he's inviting you for a work conference, just the two of you. Most of work is having good and collaborative connections with at least some colleagues, some of them will be male. I also have great female colleagues, we get on very well. Mumsnet is quite weird about being terrified if men and women interact and/or fancy each other- you are in control of the situation, he's not your boss and you can dampen down your work relationship at any time you choose.

I have good friendships at work with a variety of male colleagues, sometimes we even laugh and joke! They are not inappropriate though, and neither is this man. I don't see it as weird to get on well, even fancy another person at work, but just to be very professional and not seek out other opportunities. I don't think it means he's a sleaze or he's about to make a move though, I just don't give people the opportunity to do these things, and over the years since I got older, fewer of them have been jumping forward to be a bit weird like that, but I still have lots of male colleagues who I gel with (and many I do not).

Hmm, do you suspect he’s attracted to you because you think you’re attractive? I’m getting those sort of vibes.

I don’t think I’d think anything of this, surely this is just human beings being nice to each other?

I would be upset if this was my husband. It's clear he's singling you out so it's less about his personality and more about how he feels about you.

Is this something you have asked him to do for you or you have discussed and agreed or is it all coming from him?

I have been in a similar position but with my boss. He was/is very happily married, whereas back then, I was happily single. We got on like a house on fire. Same sense of humour, same morals, same work ethic and same bad habits (food). We hugged each other when we met, our actions didn't change in any way when his wife was around. He adored his wife.

There were lots of work related events (with clients) that partners were invited to and due to his wife's job, she couldn't or didn't want to attend and she asked me if I would go with him. I even house/dog sat for them when they went abroad.

The rumour mill started and we thought it was hysterical, as did his wife and would fan the flames by linking arms as we went out for lunch. Friends and colleagues would tell us what the rumour mill was saying and they were putting two and two together and getting 5.

Our big boss was also in on the joke but he did tell me that some people would believe the gossip and assume I was sleeping my way to the top.

But we worked well together and we understood where the line was drawn so we just cracked on. We were very good friends and work colleagues and the trust we shared enhanced our work capabilities.

I then met someone who I left the company for as he lived 4 hrs away and we married. We eventually moved back to my home town and I picked up the relationship with my old boss and his wife. We'd go out as a foursome and I'd pop into the office and we would go out to lunch on our own.

You need a thick skin sometimes, but its different for you as you are the same level so I would say trust your instincts and if they say this is just a very good platonic relationship - run with it. If you have doubts, keep it business all the way.

Good luck with your issues. I am now going to unwatch this thread