AIBU to find this comment baffling?

Yes, but the fact the expression is sometimes used for mums too makes it very clear that it’s just a colloquial way of saying a child resembles their parent.

No need to read anything more into it.

One if my dad's friends once said, "Well, you couldn't deny her. She even walks like you."

No suggestion that he ever would "deny" me (I was about 27 at the time). Just a way of saying how alike we were.

It's just lighthearted. There doesn't needed to be any drama.

It is a weird way of phrasing it, but I think it’s just a turn of phrase people have perhaps grown up with.
Im sure I read something once about babies tending to look like their fathers when born, some evolutionary phenomenon to keep the father around for protection back in caveman days (I dunno, probably made up). But I wonder if that’s where the reassuring the dad it’s his child thing comes from. I suppose there’s an element of doubt in paternity that there isn’t in maternity (technically, not realistically)

When I had my first DD everybody said she was the image of my DH brother. DH and his brother do look similar but people were constantly saying it. Thankfully she changed as is now the image of me 😃 but yes is was uncomfortable and annoying to here the comments.

Well people have said it to me ‘there’s no doubting who her mum is’ and seeing as I grew my children for 9 months, I don’t think it was really in any doubt. It’s a bit of a colloquial way of saying that my DD looks like me. I never inferred it meant anything else

Though I have five kids, four with their dad's brown/hazel eyes and one with blue eyes from my family (although my eyes are grey). Whenever anyone comments on the fact, I tend to say 'yes, we changed milkman' absolutely deadpan. There is no doubt whatsoever about the parentage of my children, but the different eye colour is very noticeable and there's only so many times you can say 'yes, DS2 takes after my family, all the others take after their dad' before you just want to raise eyebrows.

It's just a joke, I used to say I had demanded a maternity test, as DS looked exactly like DH, not hint of me there whatsoever.

Most people don't really know what to say when meeting new babies for the first time other than "he's/she's gorgeous/sweet" and other cliches so maybe they try to spice it up a bit. It's a bit hard to know how to have an interesting discussion about a new baby once you've commented on how gorgeous they are so people scrape the barrel a bit.

It’s not that deep, it’s just a joke at the father’s expense

Some people are just stupid and suffer from lack of filter. Comments when DH and I told family we were having DS when I was almost 40 included

‘Was it planned?’

‘You’re the last person I imagined having a baby!’

’An only is a lonely!’

Babies aren’t generally that interesting, and it’s kind of hard to differentiate them in terms of creating unique conversations around particular babies so people tend to stick to tried and tested (and safe!) comments.

Oh, isn’t he very like Tom?
She had a healthy set of lungs, that’s for sure!
7lbs 2oz, wow, he’ll be a rugby player like his uncle.

It’s all just well-intentioned guff and filler.

It’s just a silly joke! ‘Oh you can’t deny him!’ when a baby looks very much like dad…
it’s a joke… 🤷🏼‍♀️

I say it about myself when my kids do something that is exactly like me - it's just a comment on how alike we are!

I don’t think I understand the objection to this phrase, it’s just. colloquial way of saying the baby looks like you which is a widely accepted comment around new babies.

Yes, it’s just something people say. If they thought there were any real doubts about paternity they wouldn’t say it!

Another one I hear is “Well, he can’t deny him anyway” when baby looks like dad. (I’m in Ireland.)
The speaker isn’t actually trying to imply that there was any question about who fathered the child, it’s just a way of saying there’s a strong resemblance.

I’ve had this a lot over the years as my DS is the absolute spitting image of his dad. I went to all that effort gestating him and he appears to have absolutely none of my genes 😂

So yes, people have often said ‘Oh, there is no doubt who his dad is!’ Or they’ll say to my husband ‘Gosh, you can be sure he’s not the milkman’s!’

It’s a lame and old-fashioned joke but it doesn’t offend me in the slightest- it’s not like they actually believe I shagged the milkman! People are simply saying ‘he looks like his dad’ but trying to turn it into what they think is a funny joke. If people genuinely thought there was any doubt about paternity they certainly wouldn’t express those doubts as a public joke.

yes this I think.

Although someone complemented Ds2's (aged 12) curly hair the other day. I said ' yes- everyone else has straight hair so it's quite unusual' and the person looked at DH, winked and suggested he check out if the postman has curly hair.

I know it was a joke but I felt it was in poor taste tbh.

It's a weak joke, said in fondness.
If they actually questioned paternity, they wouldn't be saying it.

It's a really common thing to say, I'm not sure why it would cause confusion

'No doubt that it's his' sounds a bit off. Like nobody said there was any doubt?!

It seems to imply there would be ambiguity about the kid's paternity so they needed to check who it looked like?!

Like 'crikey, I'm surprised he doesn't resemble the milkman'?!

They should just say 'oh, he's got Dave's eyes/nose/mouth/ he looks just like him'.

It’s often said by people who want to claim the baby is genetically more on their side.

I think its pretty normal tbh. We all have strong family resemblance and it's common to hear Oh, he's definitely a Robinson, looks just like his dad.