Bad thoughts

So I’m dealing with this issue that’s been on my mind. I’ve been married for 4 years and I love my husband dearly. I’ve really connected with a coworker we just have a lot in common and they are fun to be around. Because I enjoy spending time with this person at work, it makes me feel guilty. It makes me feel bad always thinking about them or being excited to go to work. I love my husband, and I’m not attracted to this person but constantly having them on my mind makes me feel guilty- it makes it feel wrong. I always overthink things. When my brain tells me it’s wrong to think about them, it makes me think of even worse scenarios. Just looking for some guidance on this situation. This has happened before.