They possibly do fancy each other but that doesn't mean anything will come of it.
I worked with a lady for 9 years and we got on brilliantly. We were best mates and did end up fancying each other and admitted it to each other as well. However, we're both in relationships and nothing was ever going to come of it. I've been round her house numerous times, met her husband, spent many happy hours playing with her 2 young kids aged 4 and 1 .
I don't work with her anymore but we still keep in touch and I look forward to seeing her and her family at Christmas.
You can fancy someone without having to jump into the sack with them