Join Date: Jan 2010
Location: London, England
Programs: OnePass Platinum, *G, Amex Plat, Priority Pass Prestige, Costa Coffee Loyalty Card
Posts: 378
I've done it a few times after having had a good chat/getting along with them and knowing that they're connecting.
I've also bought my seatmate a drink with my complimentary CO coupon if I see them going for a CC, since I get loads of them and never use all of them myself (I'm rarely in Y domestically, and I don't drink a ton TATL). Never seemed to be weird to me!