How would you respond to this type of dishonesty?

S must state her case to M. If she can manage to get M in her corner, B is cooked.

^^ Bad advice. This is a mess that the boyfriend created and he is the one who has to solve it. She needs to talk to boyfriend and let him know how embarrassed and uncomfortable he has made her. He should then talk to his mother, take responsibility for his distortions and tell her the truth and try to restore her faith in the girlfriend.

In my relationships with my daughters-in-law, my sons always act as the go between and “stand up” for their wives when need be.

Just a second Birdie. If B is filling M’s head with false notions, S is entitled to a defense. Right or wrong is not the issue. B has placed the controversy in mom’s court (the judge whose opinion holds considerable sway with B) who
is planting scurrilous evidence resulting in the court’s bolstering of his position. B clearly wants mom on his side, and if the truth is insufficient in his effort, S is justified in kicking that particular crutch from under him.

M will forgive S when she sees that B is happy once again. M was only upset because B was upset. Mothers just want their children happy & will attack anyone upsetting that happiness!!! Although I believe that M will simply get over it, I think that I would insist that B tells M that he was mistaken about what he believed & that everything is OK between him & S. Mothers forgive as quickly as they attack!!!

So, is this BS or S&M?

Okay, being serious, B needs to make things right with S by manning up and telling M the real deal.

Good for you @Patty Melt. But what are the chances of B manning up as long as the soothing “poor baby”. lullaby caresses him?

The lesson in all this is – never, ever rant about your partner to a parent. It simply isn’t possible for your parent to be objective. Even if you’re 100% wrong, and your partner is completely right, your parent will take your side and be angry at your partner. Long after the incident has passed, and the two of you have forgotten everything, your parent will remember every little detail and have residual resentment.

But, B already mouthed-off to M, so what’s done is done. I’m agreeing entirely with @janbb; if B wants to keep his relationship with S, he needs to make things right with M. Regardless, M might still carry a silent grudge and never trust S again, but B should at least try. B owes at least that much to S.

The reality is that if M is worth a nickle integrity wise, she knows her son. Love may trump reason when it comes to your children, but my bet is that if B found it necessary to prejudice, M through wanton distortion of the facts, he is probably a “man” who would straighten up if M grabbed him by the ear and told him STRAIGHTEN UP.

I think S should explain to B that what he said to his M about her has been very hurtful and damaging to her, then she should tell B that they both need to go see M in person, as a couple and that B needs to explain to his M that he made those things up, and he needs to apologize to both S and his M at the same time.

If B balks at this idea, then S should break it off with him. Then she can either walk away, or go to M on her own, simply to set the record straight. No one wants to be made to feel like the villain by the false words of someone else.

M may or may not believe S, but I think it’s worth the chance to clear the air.

If B gets M involved, and M’s shallow enough to believe only one side of the story without considering the other, I’d bail. At least keep my distance physically and verbally until B wants to talk and get serious.

How I would respond, would be to have a very candid conversation with B. To continue to be in a relationship with me, B would need to hear and acknowledge what he did, get that it’s wrong and then clean it all up with M.

Since B created this problem, he may not be up for the task, at least not without taking a few courses on responsibility, integrity, and communication, which I would point him in the direction of.

B has to tell M that he gave just one side when he was venting, and that M does not have the whole picture.

Children should not vent about there SO to parents for this very reason. It’s one thing if the child has a serious situation where the SO is abusive and the adult child needs help getting out. Or, if the adult child is looking for advice and it’s not something bad the SO is doing, but rather differences that should be able to be resolved, sometimes that’s ok too, but I say it with hesitation.

I think S should talk to B and make sure they are on the same page. Does B agree that telling his mom was an error? Does he want to help straighten it out, without S having to coax him into it?

One more comment. M is older and should know that there are always many angles to a story, and three sides to the truth. It’s annoying when someone over 40 has not learned this yet. What’s the chance M’s relationships are so perfect that she would have trouble understanding that relationships are complicated? I don’t have much patience for one comment or situation ruining the entire view someone has of a person.

We don’t know the details of the incident, so we are at a disadvantage, but I’m assuming no one was cheating, or hitting, or anything that we would all see as to be at a level that is unforgivable.

S should run away from this whole whacko family as quickly as possible. Little B goes and cries to Mommy? Holy smokes, what does that tell you about the guy? This is bad news.

S should be thrilled that this happened now before it got more serious.

And she ought to get the hell away as fast as she can.

^^ Exactly! One of my cousins is in the middle of an ugly divorce from a similar “mama’s boy” and her horrendous MIL who believes that her 40 year old son can do no wrong.

My cousin should have known there was going to be a problem when her MIL offered them a honeymoon trip, as long as MIL got to come along. Luckily, they declined and paid for their own trip elsewhere, but the relationship was doomed from the get go.

I think there is a rush to judgment here. We don’t know the couple, how old they are, how long they’ve been together. The guy could be close to his mother and not necessarily a Mama’s boy. It gets far too easy to tell someone whom you don’t know to break up on the internet. How many of us walk away so quickly IRL? Besides, boyfriends and husbands have to be taught by their partners! :-)

I would advise any young woman to walk away from any mama’s boy at any time, but “the sooner, and quicker, the better”.

If a young man has enlisted his mother’s aid – and if she has given it! – to win a fight with his girlfriend, then he has poisoned the relationship, probably beyond salvage for any long term possibility.

Do we know the age of these people? We don’t know all of the details.

Better to move on from this drama while she is still single.
Imagine if they married and same problem?
the signals are showing now to leave this immature relationship as @ CWotus stated it has poisoned the relationship from now on.

Thanks, all. This has been helpful.

@JLeslie They’re in their thirties.

Yes, the adult way of dealing with it is to leave Mom out of it.

^^^ Hey, Molly, how are you, and where have you been?

It’s kind of too late for leaving the Mom out of it. Her son lied to his Mom about the girlfriend, and now she is telling her son to break up with her. The Mom needs to be set straight by her son, in the presence of the girlfriend who was lied about.