From your user name, can I guess that you are a female? I’m guessing that the animosity by the parents toward you is that you and your girlfriend are a same sex couple.
Even though same sex couples are 100% legal in the US, there are still plenty of people who are disgusted by gay people, mainly for two reasons.
The main reasons are that they really don’t understand or have any experience with gay people, and can’t believe that they are pretty much exactly like straight people (in all that entails, good, bad or otherwise). Loving someone of the same sex is pretty much the only difference, but that minor difference scares the hell out of some people.
The other reason is that some religions flat out state that homosexuality is bad, or that it’s a sin. Other similar bad stuff like divorce, lying, not treating everyone fairly or with kindness is readily acceptable with most folks in most religions. No one goes running down the street with a pitch fork (anymore) because their neighbor got a divorce. No one refuses to sell a wedding cake to a divorced person. In fact, lots of people (although not a majority) of people voted in. President who has been divorced 3 times.
So you have some soul searching to do. First, you need to have a frank discussion with your girlfriend. You need her to speak to her parents and find out the real reason that they don’t like you. Is it possible that it’s something else, and not about you and their daughter being gay? You need to know, so that you can move forth with either rectifying the problem, or dealing with the situation as it is.
If your girlfriend refuses to ask her parents why they dislike you, it might be time to walk away from her, because if she’s too afraid of them, your relationship will always suffer, and you will be on the back burner for the duration.
If your girlfriend does ask the parents, and the parents won’t give an answer, then you have to suggest to your girlfriend that SHE make some changes regarding how they treat you. She will need to spell it out to them that they either start treating you kindly, and with utmost respect, ir that the two of you will walk away (together) from her parents. If your girlfriend won’t do that, you need to walk away from her.
In the meantime, while this situation is being sorted out, do not allow yourself to be jealous (that was your word) of her relationship with her family. I’m guessing that she loves and likes her family and wants to spend time with them, as most people in any type of couples relationships want to. If she knows that her parents are treating you unkindly/unfairly, then she needs to make a decision about how she is going to lay it all out to them how that unkindness and unfairness is going to stop, immediately.
If this isn’t about them being unfairly upset with you (simply because you are gay) but if there is a possibility of their not liking you because of something you have done, then the responsibility lies with you to rectify that situation with her parents, ir for you to accept that they don’t like or trust you, and then continue your relationship with your girlfriend, as it is, MINUS your jealousy, because that jealousy will destroy your relationship with your girlfriend in the end.
I am not accusing you if having done anything wrong, the reason I’m asking about other things about you that might be upsetting to her parents regardless of whether you are gay) is because I am currently witnessing some ugly situations with people in relationships with people I know and love, who have been hurt, or been screwed over, or put in dangerous situations, and there is lots of denial going on.
Here are some examples of what I am seeing happen with friends. A sister in law is a drug addict. She had a child out of wedlock when she was young and the baby’s father died. Now, she has hooked up with a drug addict who beats her, and now they are engaged. She has been reprimanded by the court for child endangerment and neglect, but still has custody if her child. She had a restraining order against her fiancee, but that has been lifted and they are now getting married.
The mother of this person (so she is the mother in law of my friend) is an alcoholic, and so was her husband. He just died yesterday from congestive heart failure that neither he or his wife bothered to take him to a doctor or hospital when it was confirmed 2 weeks ago. They were content to sit in their house and drink, until the husband passed out and died. These same woman (my friend’s MIL) was dismayed and hurt over the years when she wasn’t invited to my friend’s home. My friend has 2 little kids and didn’t want to subject them to the drug addict SIL with the abusive fiancee, or the alcoholic MIL, who fully supported her own daughter’s choice to continue with drugs, to allow her daughter to neglect her child, or put up with an abusive fiancee.
These people would never agree with anyone’s assessment that they are trouble, and a danger to be around.
My other close friend has a daughter who is a heroin addict, and has 3 children by 3 different fathers (one of whom she’s not sure who is the actual father) and she has periodically dumped her children onto my friend, and my friend’s mother (the grandmother of the heroin addict, who has subsequently passed away). The druggy daughter has been in prison 3 times: possession and use of large quantities of heroin and selling, stealing a car and continued drug use, and theft and use of the grandmother’s debit card (while the grandmother was dying from cancer, and died a few days later) and arson.
My friend, god bless her heart, can’t understand why me and other friends want nothing to do with her daughter.
So, at this point, you need to find out why the parents don’t like you, talk to your girlfriend about your expectations of a relationship, and then make some decisions about moving on (with or without your girlfriend) and make the decision to not be jealous about situations in which you are not actually being cheated on (learn to change your perceptions about how things really are) possibly with the help of some short term therapy for you, or in conjunction with your girlfriend.
I wish you the best of luck.