If their name's not on the invitation, they're not invited

"Tag-along kids are not wanted, and the extra cost has little to do with it."

Most parents would agree that birthday parties for their children can be a costly exercise.

Whether the event is at home, or being outsourced, expenses are always calculated carefully with guest numbers in mind. (Unless you're a Kardashian, of course.)

So, when "tag-alongs", as one mum calls them, rock up, they can throw out the budget - and cause other dramas, too.

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"Tag-along kids are not wanted"

The mum wrote an anonymous online post, asking whether she was justified in being cross about "tag-alongs."

She said: "If you were having, say, a birthday party, and you invited the children, but the parent wanted to bring the child's siblings or another tag-along friend, wouldn't it annoy you?

"It would really piss me off if someone brought another child who wasn't invited with them, because my kid (unless they somehow were friends or knew each other) would barely know them and I'd think that it wouldn't be fair on said child because they wouldn't know the person whose party it is.

"Probably gets worse when the uninvited ones expect party bags and food."

Image: iStock/Mumsnet

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"The more the merrier"

Whilst it may seem in the spirit of throwing a party to think "the more, the merrier" as one commenter wrote on the post, most generally agreed with the frustrated mum.

"There is a woman in my child's class who has four kids, and all four seem to be at every party... It irritates me every time," shared one parent, for example.

Others were a bit more realistic, such as this mum who admitted, "I have been guilty of bringing my other child to parties in the past but only ever at soft play/places where I could pay extra admission. I never expect anyone to provide food/party bags for the extra child."

Individual budgets and extra costs were acknowledged by some as an annoying by-product of "tag-alongs"- but not this mum: "I don't think it's an issue in our circle - it's an affluent area and private school so parents aren't watching the budget."

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However, others respected what the original post had said about the potential impact on the guest of honour, who might know or like the "invader".

"Usually, I don't mind but when it's a last-minute or no request at all from the parents, followed by a sibling whose presence is felt for all the wrong reasons, I get really irritated," one parent revealed.

"The cake act ruining our kids' birthdays"

Looking at things from the birthday child's point of view has increasingly changed traditions. For example, when one mum recently recorded her three kids blowing out re-lit candles on their sister's cake, many noticed how the birthday girl's face kept dropping as her moment was shared with each sibling.

Viewers called the clip "heartbreaking" and "traumatic", making the point that the time to shine for one was being diluted for the enjoyment of others.

The same could be said for the "tag-along" mum's point: why should the birthday child have kids they don't know, and/or didn't want, at their party?

From the comments on the post, that doesn't seem often to be considered.

What do you think about "tag-alongs"? Tell us in the comments on Facebook.

Originally published as If their name's not on the invitation, they're not invited