A woman and two men, that are dressed professionally, are having a discussion.
A woman and two men are negotiating a threesome.
A discussion does not have to involve negotiation (progress reports, casual conversation, explanations, etc.) and certainly does not imply that the topic is about a threesome
A woman and two men can discuss things without negotiating. Discussions between a woman and two men can be about things other than a threesome. For example they could be discussion sports or business.
There is no reference to a threesome in the first sentence.