Body safety 3 year old. Need advice

[AnonymousMumMum]

Child body safety - advice needed.

My 3 yo son said to me tonight that I should do the yucky bit and wipe inside his bum. He’s never said this before. I questioned him and he repeated ‘inside.’ I asked who told him about wiping inside his bottom and he mentioned his step grandfathers name. It’s hard to know if he is telling the truth/ remembered right or even if it should be anything for concern but I’m worried.
He seems to love his step grandfather they always play and get on well. He’s his only active grand father and a great man to all of us. I just don’t know what to do. I feel like I can’t speak to my mum about this. And it may even be nothing. But there have been a couple of things now that haven’t sat right with me and this is making me nervous.
My son is too little to explain. What would you say to your child and what would you do?

what were the other concerning things ?

By inside does he mean between his cheeks?

If there 'are a few things' you're not happy with you need to raise it now. You are your child's advocate

I feel like he’s playfully smacked his bum too much. But then my mum could be guilty of that too tbf. Or been very keen to do bath time which I find odd for a step grandfather.
and he used to sit him directly on his crotch rather to the side of his lap when he was little.
there’s nothing definitely inappropriate, just a few things niggling at me. I worry I’m over thinking things.

I feel like he’s playfully smacked his bum too much. But then my mum could be guilty of that too tbf. Or been very keen to do bath time which I find odd for a step grandfather.
and he used to sit him directly on his crotch rather to the side of his lap when he was little.
there’s nothing definitely inappropriate, just a few things niggling at me. I worry I’m over thinking things.

OP do you rely on them for childcare? If not, you could ensure you're the only one cleaning his bum after toilet. I do find it odd that SG does that side of things (toilet, bath) when Nan is there. In my ILs the dynamic is definitely that MIL would take care of those more intimate jobs and that's naturally just became the way it is.
If you do rely on their childcare, I would just ask mum outright - who wipes DS bum? Based on that answer you could then try figure out what your DS means. If she says 'oh it's always SG' then you might have something to worry about. It's a tricky one because as PP said, he could have meant the inside of cheeks but I can see with the other context how you're worried. You don't want to accuse someone potentially innocent of something so horrible but also you need to protect. Hope you get to the bottom of this!

Also, forgot to add. Start the conversation about body safety and consent regardless. So many good books on this on Amazon etc. NSPCC also have good tips. Nothing too intense but start explaining what's off limits etc, he'll likely benefit from this as he will be starting school etc

I say always trust your instinct when it comes to these things