Firstly there is a distinct difference between a woman having female partners and male partners. Regardless of what some want to preach, there are physical differences and increased risks with male partners. If you want to beat this you first have to understand it might not be entirely "jealous" in nature.
Secondly there is something in men that makes them more jealous when women they are with are in reproductive age ranges. You will find most open marriages start when women are getting on in years (and hence can't or have difficulty conceiving), so the male is no longer afraid of raising another mans child as it can't happen. And there is a large segment of the poly community that follow this trend also. This is another difference between the male/females that is rarely raised. If a woman gets pregnant to another man, she HAS to do something about it, abort, adopt, raise it, etc. A man can just leave if he wants and have nothing to do with it (outside possibly paying for some of it). Stable poly relationships in where there are two or more males get around this issue simply by the fact that the men aren't likely to leave. Open poly relationships mostly have this issue.
You could tell your girlfriend you're fine with her having other men sexually after she has passed the reproductive years if she hasn't already, your jealousy should then be easier to control.
Thirdly if you aren't spending as much time with her as you would like, then her splitting up her time even more is hurtful to you. Which makes you question where you are in her priorities?
Last edited by preciselove; 01-10-2011 at 02:41 PM.