Insta-call. This guy definitely thinks you're just trying to make a move since it's the first hand. I play a massive amount HU and I find the first hand an important and unique hand that often dictates, somewhat, the flow of the game. I think the first hand is almost a seperate game to the one you play from the second hand and on.
Here are my own personal rules for the first hand:
1) Only raise premium group I hands. Raising the first hand immediately gives your opponent the impression that you're going to want to be aggressive. Yes, you want that but, and it's happened so often, they'll say to themself, "Raising the first hand...I'll show this guy!" and repop. Too many opponents don't believe you in the first hand moreso than any other hand. They will call down very light on the first hand so make sure you've got the goods if you were the preflop raiser.
2) Always Always play the hand and never fold it even to a std. raise pre-flop. I don't care if I've got 72o, if my opp is making a std. raise, I'm calling it and I will even call a flop bet with complete air. Gives the impression that you're not going to roll over and get [censored]. In turn, it's often the case that they've got complete air so I find the first hand the easiest of the lot to bluff at on the later streets. Your opp wanted to be all TV-aggressive (I'm coining that phrase
) but when he realises you're calling the flop bet too, more often than anytime throughout the game, they will slow down and you can resteal.
I think the first hand is really overlooked because "it's the first hand". Don't do that. I think it can dictate your image and the flow of the game to small part.
Back to the hand - yes, instacall.
GL