I'm not really sure what it is that is going on in my brains
I talked to my husband about this last night and it's not making any more sense to me.
In short, I am in a triangular relationship with my husband and gf. My relationship with her is great, there are no issues on that count from any of us. Husband is happy for us, willingly gives us time together, no jealousy, save that he would quite like to join in (never gonna happen chaps...). She and I have a very romantically based relationship, things are good.
My relationship with my husband is, being worked on. He has a very high sex drive, and the NRE when we got together may have given him false hope for the future. I physically can't keep up with him, not consistently. Certainly not with a toddler and another baby on the way. I don't have the sex drive I did, and I don't have the urge for kinky stuff I did, still some, but not the heavier D/s we once did. Part of the reason for the poly in our relationship was so he could have his needs satisfied, and get back to having a more affectionate (rather than a frustrated and gropey) relationship with me. That worked. Actually it works both ways, he sees GF and is all lovey and chilled with me, I see GF and am high on oxytocin, and he is being nice to me, our sex life is better. Brilliant.
Their relationship is very BDSM based, she has told me that she feels bad for not giving him any affection (but we got over that when we agreed that was what I was for, and she didn't have to feel like she had to fulfil that role if she didn't want to) and that in her words "if he stopped beating me I wouldn't let him touch me". Essentially it is about them getting their S&M kicks, playing punishment games etc, and both of them are very happy with that.
I don't ask for details, but sometimes stuff filters through, I am aware of the dynamic of their relationship, and some of their activities. On the surface I am very happy for both of them. But sometimes, I get an intense feeling of sad.
When it was just the 2 of us, it never really bothered me that there were things he wanted to do that I didn't, it was never an issue, some stuff he liked was outside my limits, end of story. Sometimes I didn't feel like stuff, other times I did, such is life. Now that he is able to get that from someone else though, I feel sad that there are those things that he can't share with me. I feel like I am not doing my duty as his wife almost, and a bit crap that he had to bring someone else in to pick up my slack, so to speak. In a Relate session he once said to me that he wouldn't want to be with anyone else if he could get everything he needed just from me. I feel like I am letting him down somehow, even though I know I simply cannot do that.
I want to be happy for them both, that they are able to get the things I can't give either of them, and mostly I can be, but I broke down in tears yesterday because he told me to expect a parcel of BDSM stuff in the post today and I knew it wasn't for us, but felt it should have been. I'm not sure if this is a proper issue, or just part of the settling in process. We had a bit of a rocky start (I found out he had been unfaithful in the past, and then that he had been sleeping with GF before discussing non-monogamy with me), and I am not sure how much of that is seeping in either, though I thought we were past that.