It wouldn't be a problem to only have MFM scenarios if that's all you are wanting.However, because it sounds like you may want to explore with another woman,you do need to sit down with your wife and discuss this with her.Explain to her that you feel somewhat of an imbalance and in no way are you upset with her or anything of that sort...you just would like to experience another woman...as she has experienced other men.She may not go for it and you need to ask yourself if you'd be alright with things exactly the way they are now.It just seems like you are feeling a bit cheated,{Not that you aren't enjoying revelling in her pleasure and pleasing her,etc.},it's just that she is having all this fun and receiving all the attention from you and the other men and perhaps, you would like to feel the same way and be on the receiving end as well.