what are some tips to get into the next step, phase of this?
.... Gronky, I don't think you may have been "clear enough" with her as to what needs to happen if she's to satisfy your request. For all you know, she may have already had sex with other men since you asked her. What you really want, however, is to SEE her have sex with another man. Its the only real way you'll be satisfied if you think about it. She has more at risk by being sexual with other men ... plus, she may value her relationship & marriage with you and wish not to chance changing the relationship. Women are quite emotional, thus if she gets involved with other men, there's this chance she'll desire more than just sex from it later on. So, the key, I feel, is to spell out exactly what it is that you desire happen, and keep it all up front, otherwise, you'll possibly never benefit from her sexual relationships elsewhere.
.... My wife always seem to enjoy the 3-somes more than anything outside our normal sexual relationship. Not a gangbang or couple swap, as those seemed to be too complicated to arrange or overwhelming. So, talk more specific about taking that next step by arranging a 3-some. Most women who are into sex outside the marriage, feel a bit more secure and comfortable, especially early on, in their husbands being there. If SHE doesn't wish to invite a man, then take it on yourself, once she's agreed to a 3-some. After she's become comfortable with 3-somes, maybe she'll be willing to take on bolder relationship.