Thor went to take another step but Sif had stopped him with a touch on his shoulder. "You are not offended?" Sif had asked cautiously, not knowing what to think about this Loki. Thor had his hammer, Mjolnir in hand when he had summoned it. Not trusting Loki like he use to. But now Thor had a family and rule a great Kingdom. He needed to protect them. 

Diaval actually didn't mind being petted like some pet. It felt nice and Loki didn't do this offer so there was no harm or foul that way. Diaval however didn't show how much he liked Loki petting his head.