Am I over-reacting?

My boyfriend has a dog, who I adore and show lots of affection to, but my boyfriend makes these comments that really bother me. For example, I was touching the dog with my feet, trying to get him off the bed (we were about to have sex), it was very playful. My foot was under him and I was gently lifting him with my foot. I was not hurting the dog. My boyfriend says, "don't kick my dog." He makes these comments frequently and I take it personally. I finally said something to him and it turned into a thing, of course. What do I do? Am I overreacting? It just makes me feel so self-conscious because it makes me think that he believes I have un-pure motives.