other girlfriend - boundaries?
I've posted here once before in the relatively early stages of my current poly relationship and really appreciated the advice I got from everyone. My boyfriend and I have been together for almost a year now and since then we've done a lot of communicating whenever something bothered me and I feel like I can tell him anything without either of us escalating it. As a bit of background, he's been dating a married woman for over three years and I've met both her and her husband and we all hang out regularly.
So now I have kind of a boundary problem. Whenever we're at parties or just hanging out with a group, my boyfriend and I sometimes cuddle together. On the couch, lovesack, occasionally someone's bed. All their friends know about the whole poly thing so it's not really out of the ordinary for his other girlfriend to come over and cuddle with him from the other side and be all touchy-feely. Now it's well established that I'm his primary and her husband is usually present at these events and sometimes not doing much of anything. So I get uncomfortable when she comes over and, to put it crudely, moves into my territory :P. Sometimes I'm just relieved whenever we start cuddling and can be alone for more than 10 minutes. I myself am not very actively poly so I really value alone time with him, even if it's at a party. By alone time, I mean that I'm the only one he's intimate with. I know he and his other girlfriend have their own time together (albeit not as often) so even at parties I want to feel exclusive. I don't think it's a lot to ask (and neither does he), since his other girlfriend does have a husband.
I don't know if this kind of thing is crossing a line or if I'm just demanding. I often do feel very irked when this happens. She is always the one that initiates it, since my boyfriend has told me he thinks it's reasonable that he only be "with" me at parties and such. So far I've just gone along with it. I don't think she realizes that this bothers me, otherwise I know she wouldn't do it. But at the same time I am very bad at confrontation and am surprised that she hasn't been more sensitive to how I might feel (selfish as that sounds) considering this is my first poly relationship and that I'm his primary. Of course, I have pretended to be fine with it for this long so I do have to take some responsibility. I can already sense that a lot of peoples' responses will be that I should talk to her directly since it's not my boyfriend doing this but I really can't think of a way to do this without sounding bitchy. We're very friendly with each other and since I've never brought this up before it might seem very sudden to her and possibly even demanding (imagine if someone was telling you to back off out of the blue, from a guy you've known and dated for way longer than her). Thanks in advance for the help!