Apologies in advance for the length of this post, I don't want to drip feed.
I have two DSis, we're all very close, live close by and see a lot of each other. I have a toddler DS. DSis1 has a newborn DC. My DSis2 has no DC, but definitely wants DC and split with her long term BF a year ago due to his lack of interest in having DC any time soon.
Three months ago DSis2 met a new BF, they're crazy about each other, things have moved quickly and they're now happily living together. He has no DC but has told DSis2 he's keen to settle down and have DC with her in the near future. I think he's definitely 'the one' for DSis2. I'm really happy for DSis2 about this because she's the happiest I've seen her in years, she's positively glowing. So far, so good. BUT...
The one thing that's stressing me out is that this new BF is way too full on with our DC and keeps on overstepping the mark. I think it's because he's absolutely desperate to impress DSis2 and us, which is really sweet and admirable but it's just getting to be too much and starting to really grate on me.
Every time we see them he spends all his time manically following DS around trying to entertain him in a very OTT performance type way, even when DS is clearly not interested and either trying to do his own thing or play with someone else (like me, DH or DM). He's also constantly making suggestions to Dsis1 and I about how we should care for our DC. Some examples from the last week include: on a car trip DS started grizzling a bit as he was napping but had a cough that kept waking him up, I asked DH to pull over the car so I could administer some cough medicine to enable DS to sleep, but the BF said 'are you sure it's just his cough, is his nappy too uncomfortable for him, maybe you should change it', I told him no, I'd changed it just before we set off 20 mins ago and it wasn't dirty, so he then said 'maybe you should stop at a shop then and get him some other types of medicine, the stuff you've got might not be enough on its own'. At a family party DS hadn't napped as he was overexcited to see everyone and started to grizzle, I was in the process of putting him in his push chair so I could talk him for a walk outside to get him to nap and helpful BF came over and said 'are you sure he's not too hot, maybe you should take his jumper off and get him some fresh air'. Then at a supermarket I got DS out of the car and put him in his pushchair while DH got the changing bag from the car, BF walked over and just took the pushchair with DS in and without a word started walking off ahead of us. Then yesterday DSis1 got a little weepy as her DH is going back to work after paternity leave and she was telling DSis2 and I that she was understandably nervous about coping alone for the first time and BF chimed in with a very dismissive 'you'll be fine, newborns aren't hard to look after, all they do is eat and sleep'. Hopefully this paints the picture, but there's lots more examples from the last 3 months.
I've not said anything to DSis2 as she's so happy and would be mortified to know how irritating I'm finding all this. I've also not discussed it with DSis1 as I don't want to make it into an us vs him situation. My DH has however confided in me that he also finds it irritating and both of us have on avoided spending time with him (and consequently DSis2) a few times because of it.
So I guess what I want to know is WWYD? I don't want to lose my closeness with DSis2 or rain on her happiness, but at the same time her BFs over helpfulness and apparently superior parenting abilities are driving me up the wall. Should I say something to make him tone it down and risk upsetting both of them, and if so what do I say? Or do just suck it up and hope that, as DH has suggested, over time he relaxes and stops desperately trying to impress everyone, and if they have children he'll either realise how annoying his comments are or be too busy with his own DC to be so concerned with our DC?
It's difficult cause I'm certain his behaviour is coming from a good place and he's actually just very insecure and trying to prove himself to us and DSis2, but it's just so hard to remember this and not let it drive me nuts! I really want to like this guy for the sake of my amazing DSis.