DS1 is 2.11, and (admittedly) has got away with a lot more whinging than is acceptable because DS2 came along and was a poor sleeper, and I couldn't be bothered to fight it 
However now we are clamping down on "whinging does not get you what you want", but I get stuck when we are out...
Generally when we meet up with friends and thier kids (so children he knows, but he doesn't particularly have 'friends'), at playdates, the park, playgroup etc; within 20 mins he's hanging off my clothes, pulling my arm, and whining "I want to go home". I've tried to persevere with whereever we are, but I just look a fool trying to keep a toddler in a playgroup when he doesn't want to be there.
I'm not denying that I'm probably ignoring him, because I want him to play on his own / with other children for a bit; and because DH works away at lot, and it's often the only chance I get for adult conversation...
Help / advice please