'Or do we provoke the Lord to jealousy? Are we stronger than he?'
By not fleeing from idolatry they are provoking the Lord to jealously (the symmetry of the passage connects the two statements). He thus compares the act of eating in pagan temples with lovers seeking to make their partner jealous by consorting with another. Is that what they are trying to do, make God jealous? Do they really think that they are so mighty that they can treat God in that way?
Or perhaps in the light of Deuteronomy 32:17 he is simply pointing out that they are deliberately rebelling by approaching false gods even while they pretend to worship the true God, and thus stirring God's 'jealousy', His concern that His people should only look to Him (Exodus 20:5). For In Deuteronomy 32:17 we read, 'they sacrificed to demons which were no God, to gods whom they knew not, whom your fathers did not fear' and this is followed by (1 Corinthians 10:21), 'they have moved me to jealousy with that which is not God, they have provoked me to anger with their vanities, and I will move them to jealousy with those who are not a people, I will provoke them to anger with a foolish nation.'
These foolish Corinthians, he suggests, are behaving just like those foolish Israelites of old (compare 1 Corinthians 10:5-10) and may therefore bring on themselves the same judgment, that God will show favour to others who are not His chosen and not to them who think they are. They are thus choosing their own way in defiance of God and thereby giving the impression that they think themselves stronger than Him. While what they are really doing is flaunting God.