Okay…so a couple comes over for dinner and graciously brings a bottle of wine…what’s the protocol here?
Do you so, "Oh, what a lovely bottle …we’ll be sure to save this until our yet-unconceived child graduates(or some equally momentus occasion worthy of their offering)or; do you pop it open right there on the spot just to show them how grateful you are and that you too can be gracious by sharing it with them?
The whole thing is just fraught with social peril.
It seems that there may be a risk of offending the giver by a) drinking it rather unceremoniously while watching the hockey game with them or b) stowing it away from their greedy lips and serving them your own wine, which they in turn may interpret as an indication that you prefer your own swill to their’s.
My only thought on this is that the dinner party host would have assumedly selected the wine with the meal in mind whereas the guest couldn’t have known what was for dinner, so there is an “out” - albeit somewhat awkward - for the host to uncork his/her own hooch.
The other option would be to get busy drinkinjg until everyone forgets who brought what.