"question is would it be selfish of me to ask that sometimes it be just me and her?"
I don't think it's "selfish" per se, but I think it's going to be delicate and needs to be approached slowly & with compassion for everyones feelings. It's something they will need to talk about in depth and they will need to feel sure that your intentions are pure and that it's not an effort to try to drive a wedge between them. Not knowing her husband it's impossible to project any insecurities he may have that he'll have to face but given his comfort level with watching her with someone else I'd suspect that over time he'd be quite comfortable with not being present. PROVIDING he trusts you
I agree with this, BUT I also have a very strong belief that one-on-one connections are important in our lives and relationships. I believe that all members of a relationship should be able to spend time one-on-one time with each other (as they choose to - i.e. you don't HAVE to build a relationship with a metamour).
Also I would assume that your partners know and understand that you don't consider yourself poly and have come into the relationship still from the perspective of a one-on-one relationship with her.
So IMO, you should be able to ask to spend "couple" time with her w/out drama or repercussion.
Of course "should" doesn't always work in real life.
So given that, I'd say that approaching the topic delicately and with the understanding that you're not in any way attempting to influence their relationship, you'd just like a "share" of her time outside the triad ... that would probably work best.
As far as asking her not to sleep with someone else, I think that's trickier. You met her in a swing club, you said, and you knew going into it that she's poly ... so IMO, at this point asking her not to sleep with anyone else would be like ... I dunno, going to a steak restaurant and then complaining because they served you steak, you know?
As GroundedSpirit said, you need to make sure that asking her not to do that is based on HER safety vs. your insecurities or needs or wants.
FWIW, you say that you consider yourself mono, but you are in a fairly intense poly relationship (all of you sharing the same bed, etc.). I'm wondering if you feel that to call yourself poly, you have to have more than one relationship yourself? I know my husband is beginning to accept that he is poly ... even though HE does not have a secondary relationship, simply because he is involved with me and I am involved with others. Because he is willing to accept the life and be part of my connections, he considers himself to be poly by association.
It doesn't mean he has to have another partner ever, if he doesn't want one.
But bottom line is this: I've found out that poly is a very broad area. There are more ways to practice poly than I would have ever imagined when I first started learning about the life. And the nice thing is that none of them are technically "wrong" or "right" ... they're just different ways that different people structure their romantic relationships.