I think you will have to actually explain that partners are not invited, we invited someone to the wedding (without knowing she had a partner) and put only her name on the invite and she replied back saying that her (and her partners name) would love to come! I thought it was a bit of cheek personally - I think she should have called and we would (as we did) happily have had him, but my point is that people assume partners are invited.

I think generally speaking protocol is to invite partners, but as it's work mates (unless they are a bit precious!!) I think they would probably understand - as long as it is consistent with all partners not invited you should be fine.

If I were invited to a wedding of a work friend, I would not be offended if DH was not invited - although i would prefer to have him with me, it would also be fun to just have the work girls there to 'play' :-)

I found it difficult to decide who to invite and what to do with work friends - in the end I just invited two girls and their partners and then invited another two and their partners - on the B list - after some people couldn't come I apologised for the fact that they were invited 'later' - but they were still really happy to come along.

A few others came to watch the ceremony without their partners - and it was nice to have them - but as you say, it's hard to know who to invite, and worry about not offending people :-)

good luck with whatever you decide!